At a meeting at Cwm y Glô during February 1922, the Eryri Football League was formed, the founder members were Rhythallt Comrades, Glasgoed Rangers, Llanberis United and Ebenezer. Soon after Rhythallt Comrades and Glasgoed Rangers amalgamated to form Llanrug Football Club, and were members of the Welsh National League - Division III (West). The home fixtures were played at Cefn Llwyd, and in that very first season the club reached the final of the North Wales Coast Football Association - Junior Cup. The match was played at Colwyn Bay, but unfortunately Llanrug lost the match by four goals to nil against a very strong Oakenholt side. A grand total of £28/1/1½; profit was made by the club during that very first season, which is equivalent to about £28.06 in today's money - the travelling costs alone totalled £64/2/10 (£64.14).

During the 1924-1925 season the name Llanrug United appeared for the very first time, and the following season they were the Welsh National League - Division III (West) champions. In the 1926-1927 season Caernarfon Football Club joined the Welsh National League 1st Division, and for some reason or other Llanrug United did not have a team in the league, and as a result there wasn't a league side in the village until the 1932-1933 season.

In the meantime, during October 1933, a new playing field was given to the village of Llanrug by the Mayor of Caernarfon Mr D. Elliot Alves (who later donated the famous Alves Cup). Mr Alves was the proprietor of the Bryn Bras Castle on the outskirt of Llanrug. The following year during a meeting at the Memorial Institute, Llanrug Institute Football Club was formed, initially to play friendly matches, and eventually they joined the Bangor & District Football League for the 1932-1933 season. Mr Alves was elected as the club's president, and the home fixtures were played on the new 'Recreation Ground' which he donated to the village.

This is the first season on record that a fixture took place between local rivals Llanrug and Llanberis, the score being - Llanberis 4 - 1 Llanrug Institute. At the end of the season Llanrug were fourth and Llanberis were fifth in the final league table. In October a North Wales Coast Football Association - Junior Cup 1st Round tie had to be switched from Llanrug to Trefor, because the Recreation Ground was not up to the satisfactory standard required. A dance evening with the Hedley Moffat Band was held during December at the Church Hall, to raise fund for the club.

During a North Wales Coast Football Association meeting in June 1934, it was reported that numerous illegal football matches were being arranged in several areas outside the official football season. It was decided not to allow those participating in these matches to join the League in the forthcoming season. Many of these illegal matches were staged at Llanrug, and as a result five players, and all the officials of the club and the pitch were banned from the League. But by September in the same year, the ban on the officials and the pitch were lifted, as it was proven that they had no connections at all with the matches played during the summer months. The pitch belonged to the village of Llanrug, and the football club only had a privilege for its use between the hours of two and five on Saturday afternoon during the winter months.

In April 1937 the club resigned from the Bangor & District Football League, and the following season the League was abolished, due to lack of interest and support. The club did not join any League between 1937 and 1939, and for a very prominent reason no football was played at any level between 1940 and 1945

The club was re-established as Llanrug United for the 1945-1946 season, and they joined the Welsh National League - Division III (West). But unfortunately the following season, as a results of complaints that the 'Recreation Ground' playing area was to small, the club were resigned to join the re-established Bangor & District League, and the home fixtures were played at 'Parc Bailey'. On Christmas day 1946, Llanrug gained a famous local derby win by three goals to one against Llanberis, and at the end of that season Llanrug were crowned champions of the Bangor & District League.

There was no end to the ground problem, and the following season the club had to switch back to their very first home at Cefn Llwyd. At the end of the season the Alves Cup was won at the Oval, Caernarfon, by a margin of four goals to three against Nantlle Vale. A great feast awaited the players and officials after the match at Bryn Bras Castle.

One of the local stars of the period was the Llanrug centre forward Emlyn Jones, and in April 1949 he was invited for trials at Bolton Wanderers for the third time. At the end of the season, following a nil-nil result after extra-time at Farrar Road, Bangor the League Challenge Cup was shared between Llanrug United and Portdinorwic.

The following season Donald Kimlock Macdonald from Bangor was appointed player-manager. He was a native of Glasgow, and had vast experience of playing professionally in the Scottish National League with Dunfermline. The League Challenge Cup was won again, by a margin of four goals to one against Llandudno Reserves.

The name of centre forward Emlyn Jones was prominent again in January 1951, when he scored eight goals for Llanrug, in a demolition match of fourteen goals to nil against Bethesda, it is believed that this record still stands today.

The problem of having an adequate pitch to play on was on going major headache for the club. At the commencement of the 1951-1952 season the home fixtures were played at Pontrhythallt, on land owned by Tan'Rwylfa Farm. Unfortunately the pitched proved to be totally in-adequate, and the club switched there home fixtures to Dôl Helyg. This ground was considered to be one of the best on the North Wales Coast, but once more for some apparent reason the club had to move and play at Parc Rhôs the following season.

In October, 1953 the club could not find a suitable and adequate pitch to play their home fixtures, and as a direct result had to resign from the league. Local rivals Llanberis also resigned, the supporters numbers were scarce, its was thought at the time that the introduction of the sport television programme 'Grandstand' was keeping them all indoors on Saturday afternoons.

The club re-joined the Caernarfon & District League for the 1954-1955 season, but the following season, there was no team in the village of Llanrug. The club re-joined the league for the 1956-1957 season, but unfortunately as a result of a lack of interest and financial problems the Llanrug United Football Club resigned from the Caernarfon & District League at the end of the 1958-1959 season, there wasn't a team in the village thereafter for nine years, until the re-emergence for the 1968-1969 season.

On Tuesday night the 7th of June, 1968, in a public meeting at the Memorial Institute Llanrug it was unanimously decided to re-establish the Llanrug United Football Club. And in that meeting the following officers were appointed, John Lewis (Anchorage) as Chairman, the Secretary was Arfon Davies (Ty Capel), and Alan Vincent Owen (4 Rhos Rug) as Vice-Secretary and Evan Owen (Ty Fry) as Treasurer.

The club joined the Caernarfon & District Football League for the forthcoming 1968-1969 season, and the home fixtures where played at Eithin Duon. Other teams in the League were as follows: Bethesda, Llanberis, Caernarfon Town Reserves, Talysarn Celts, Nantlle Vale, Llechid Celts, Mountain Rangers, Pwllheli, Harlech, Hirael, Criccieth, Nefyn, Penrhyn and Caernarfon YMCA.

Therefore, during the summer months a squad of players were assembled to represent the club, one of the first players to sign was R. Arwyn Roberts, a left winger who was with Llanberis the previous season, and Arfon Lewis who had played as a centre forward for Caernarfon Town Reserves. Another to register was Alan Vincent Owen who had vast experience of playing for Caernarfon YMCA, Llanberis and Mountain Rangers, others to register were Ritchie Owen, Gwyndaf Lewis, Gwyndaf Roberts and John Ian Jones.

And on the 23rd of August, 1968 the first competitive league match was played by Llanrug United at their new Eithin Duon ground, and the visitors that afternoon were Nantlle Vale Reserves. The players selected to represent the club were as follows: Tom Pritchard, A. Bendlow, Alan Vincent Owen, Alan Jones, Arthur Wyn Hughes, R. Arwyn Roberts, John Walsh, Robin Bowden, E.G.Owen, Arfon Lewis, Gareth Jones. Llanrug won the match by two goals to one, with R. Arwyn Roberts and Arfon Lewis scoring for the home side. A large crowd supported the team that afternoon, this was the first competitive league match in the village for nine years, gate receipts that day added to £17.00.

During this period the club decided to promote youth football in the village, with the intention of establishing a youth side in the league the following season. And in 1970 a Llanrug United - Under 15's side joined the Gwyrfai Junior a Football League. Also during this period the club purchased a wooden hut from Porthmadog, and re-built it at Eithin Duon to be used as changing rooms, for the both set of players and the match officials. For a very short period the club returned to their original ground at Cefn Llwyd, while Eithin Duon had to be ploughed and re-seeded. And after returning for the 1971-1972 season they were crowned Caernarfon & District Football League Champions, they only lost one league match throughout the season. And the following season1972-1973 they lifted the Alves Cup.

At the end of 1972-1973 season, Eithin Duon was purchased by the club officials, and immediately the playing surface was levelled by a professional company at a cost exceeding well over a thousand pounds. As a result the home fixtures for the 1973-1974 season were played at the Brynrefail Secondary School field, that season the club finished a creditable second in the league, and therefore lifted the Deanfield Cup.

The trophy cabinet proved to be rather empty thereafter up until the 1977-1977 season, when Howyn P Jones was appointed as player-manager of the club. He had vast experience of playing professionally with Wrexham, and also had a season playing professionally in Australia, and he also played for various leading clubs in North Wales, notably Bangor City. At the end of the first season, Llanrug were the Caernarfon & District Football League Champions, the NWCFA Junior Cup winners, Penrhyn Cup winners, Marconi Trophy winners, and the Fair Play Trophy winners. The following season they retained the Caernarfon & District Football League title and also the NWCFA Junior Cup.

At the end of the 1978-1979 season, Howyn P Jones resigned as manager, and the trio of his players Gwynfor Owen, Peter Roberts and Vernon Lloyd took over the management role. Unfortunately no success came their way that season, and it remained the same up until the 1986-1987 season, with Dafydd Arfon Jones and Peter Casey in turn taking over the manager's role. Then in the 1986-1987 season the Gwynedd Football League was re-established, and as a result Llanrug United joined under the management of Mike Kennedy. A Reserve side was also formed to promote local youngsters and R. Melfyn Jones was appointed as manager.

The following season 1987-1988, Dafydd Mona Owen was appointed as manager of the first team to follow Mike Kennedy. And for the 1988-1989 season Howyn P Jones joined forces with Dafydd as a management duo, while veteran Gary Davies took on the role of player-manager of the Reserves. That season the Llanrug United Reserves were crowned Caernarfon & District League Champions and were also losing finalist in the Wil Evans Cup.

On a Friday evening in June 1991 an ever-memorable match took place at Eithin Duon, its was the final league match of the 1990-1991 season, and Llanrug had to win against University College of North Wales (Bangor) to clinch the Gwynedd Football League Championship from the grasps of Machno United. The teams would be level on points, but Machno's goal difference was far more superior, therefore Llanrug had to win against the students by twelve clear goals. Among the well over three hundred crowd at Eithin Duon that evening were the Machno United officials, ready and waiting to receive the League Trophy. But the were well gone on their way home, when Llanrug clinched the title by winning the match by seventeen goals to nil !!!!

The following season 1991-1992, the first team finished second in the league and therefore received the George Lovatt Cup, they also achieved a cup double by winning the Eryri Shield and the Gwynedd Cup. While the Reserves under the management of Kevin Wyn Owen won the Deanfield Cup and were losing finalist in the Moorings Cup.

Following the resignation of Dafydd Mona Owen and Howyn P Jones, two former players Maldwyn A Williams as manager and Ken Jones as assistant were appointed for the 1992/1993 season, and United went on gain a very respected seventh position in the league.

United failed to shine during the next few season's, with several individuals trying their hand at the management helm, John Williams, Ken Jones, Eilian Williams, Percy Allen and Stuart Williams. The later stepped down in November 1997, and long serving reserve team manager Kevin Wyn Owen took over. United did reach the final of the Eryri Shield at the end of the 1997/1998 season, but lost to League Champions Amlwch Town at Meurig Park, Bethesda.

The following season the President Cup was won by beating Pwllheli in an enthralling penalty shoot-out at the Traeth, Porthmadog, were the scores had been level 2-2 after extra time. In the 1999/2000 season a very respectable 5th position was achieved in the league.

United received the George Lovatt Shield for the 2000/2001 season, for being runners-up in the Gwynedd League, losing out on the championship on goal difference to Felinheli. Also that season United were losing finalist in the Eryri Shield, losing 5-3 in extra time against Bodedern at the Oval, Caernarfon.

The 2001/2002 season proved to be a disappointment, an 8th place finish in the League and Kevin Wyn Owen stepped down as manager in the summer of 2002, after five seasons at the helm.

Long serving player Gwyn Davies was appointed as the new manager in August 2002, with Dafydd Mona Owen as his assistant. And in their first and only season at the helm together, United were crowned champions of the Gwynedd League and winners of the John Smith's Gwynedd Cup.

Following ground improvements at Eithin Duon, which the club undertook at their own expense, United were prompted and accepted as members of the Welsh Alliance League for the 2003/2004 season. Dafydd Mona Owen was appointed as manager with Kevin Wyn Owen as his assistant, United finished their first campaign at the higher level in a respectable mid table position. And were losing finalist in the Alves Cup in a final played at Conwy, were Bethesda Athletic won 4-2 after extra time.

The 2004/2005 season proved to be a disappointment, an 13th place finish in the League and Dafydd Mona Owen stepped down as manager in the summer of 2005, after a couple of seasons at the helm.

In July 2005 Aled Owen was appointed as the new manager for the 2005/2006 season. Owen originally from Porthmadog but has lived in Llanrug for many years, is a well respected player and coach, who was at Llangefni as a 1st team coach for the 2004/2005 season in the Cymru Alliance, this after a distinguished career at the top tier of Welsh football as captain of Porthmadog FC. United finished the season in a very respectable 8th position.

Under the management of Aled Owen and his assistant Kevin Wyn Owen, the following seasons United achieved a commendable 7th, 6th, 8th and 8th position in the Welsh Alliance League.

The 2011/2012 season was the club's 9th consecutive within the Welsh Alliance League, having finished a disappointing 13th position last season, United impressive run-in of seven of seven matches without lost lifted them to an impressive 6th position in the Welsh Alliance League.

Aled Owen remains as manager for the 2012/2013 season, this being his 8th in charge.