Lannon was a product of the Salford Red Devils' Academy System where he also subsequently captained the side.

Lannon made his début for the Salford Red Devils in a Super League match on 12 April 2015, the game was played against the Leeds Rhinos.

[3] Lannon has featured for several clubs on a loan basis namely, the North Wales Crusaders (2016), Halifax (2017) and Oldham (2018).

[citation needed] In October 2018, it was announced that Lannon had signed a three-year contract to play for Hull Kingston Rovers commencing in 2019.

[4] On 17 February 2019, in a round 3 fixture against the London Broncos, Lannon made his Hull Kingston Rovers début at Craven Park in a 22-12 victory.