Ireland. Thornton signed along with former Athlone Town player Sean Brennan. Thornton made his debut against Bray Wanderers in a 1–0 away win. In his next game Thornton set up the winner with a free kick in a 3–2 win against Sligo Rovers. On 26 November Thornton re-signed with the club on a year deal. He said "I am looking forward and determined to get the club back into the top tier where it belongs." Rathmullen Celtic FC Upon seeing his contract out with Drogheda United Thornton was snapped up by newly formed Non League side Rathmullen Celtic who play in Division 3 of the NEFL. Under the guidance of Chairman Robbie McDonnell and manager Stewie Barnett Thornton masterminded promotion to Div 2 for Rathmullen after reproducing arguably some of the best form of his career. Scoring 28 goals and assisting 14 in an advanced midfield role . However Thornton never got to play Division 2 football with Rathmullen after a pre season of upheaval seen the club go into administration before the new season began. Athboy Celtic With Rathmullen folding Thornton became a free agent and hot property in the NEFL. Thornton decided to train alone keeping his fitness levels up by cycling and power walking around the locality until the right offer came in. That offer arrived in the shape of Athboy Celtic. The Meath club currently playing in Division 1 and under the guidance of local football guru Derek Kavanagh enticed Thornton back into the game with the mouth watering prospect of bringing them Premier Division football. The news spread like wildfire through Athboy and a crowd of around 18 locals lined the streets to welcome the new signing at training on Tuesday night. Unfirtunately for Thornton and Athboy they finished outside the automatic promotion places and remained in division 1. Newfoundwell FC After one season at Athboy which resulted in a failed promotion attempt Thornton followed manager Derek Kavanagh to the premier league of the NEFL and to 2017 treble winners Newfoundwell FC. The stay at the Well was short lived though as after failing to field a team in 2 separate matches the club were disqualified from the league and effectively disbanded in May 2019. Moneymore FC Thornton again found himself as a free agent and with the transfer window opening on 1 June 2019 he had the opportunity to sign for any NEFL club.