An elegant midfielder from Belfast, Fallon is a former Northern Ireland youth international at U16, U17 & U19 level, where he first worked with Linfield manager David Healy.

Stephen started out playing locally with St Oliver Plunkett FC and was there from the age of 10 up until 16. He was spotted playing there by a Swansea City scout and, following a successful trial,

he signed for Swansea City in 2014 when aged 16 and went on to play for the Swans’ youth team, as well as making 15 appearances for their reserve team.

He arrived at Linfield initially on loan in the January 2016 transfer window, initially as a player who played on the right of midfield. David Healy secured his signing on loan from Swansea for the second half of the 2015-16 season. Fallon made his debut in a 4-0 home win over Ballymena United on January 23, 2016. His first Linfield goal came in a 7-0 home win over Armagh City in the fifth round of the Irish Cup on February 5, 2016.

Fallon made nine appearances on loan, scoring once before returning to Linfield on a permanent basis in the summer of 2016, signing a two-year deal with the Blues following the expiry of his contract with Swansea City.

The midfielder was used sporadically in his first couple of seasons as he developed physically and adjusted to the physical demands of the Irish League before a breakout season in the 2018/19 season when he was named as Linfield’s Young Player of the Year. Fallon became a regular playing central midfield in the Linfield team and was then named as the Linfieldfc.com Player of the Year for the 2019/20 season.

Over the following seasons he remained an influential and creative figure in the Linfield midfield before an unfortunate run of injuries which saw his appearances limited in the 2022-23 and 2023-24 seasons.

Fallon has made more than 200 Linfield appearances and is contracted until the end of the 2024-25 season. He has won five League titles, two Irish Cups, two League Cups, one Co. Antrim Shield and a NIFL Charity Shield with Linfield.