Galligan made his club debut in 2002 and was on the Lacken team that faced Drung in the final of the Cavan Intermediate Football Championship in 2004, scoring a point in their 1–9 to 1–8 win.
[4] In 2016 Galligan captained Lacken from full forward to their first ever Division One league title, defeating Kingscourt Stars in the final.
Galligan joined the senior team in 2006, making his debut as a substitute against Antrim in the Tommy Murphy Cup.
[7] Ahead of the 2015 season, Cavan manager Terry Hyland tried Galligan as a goalkeeper because of his kicking ability.
[10] On 3 April 2016, Galligan kicked two 45s against Galway in the National League, as Cavan earned promotion to the top flight for the first time in 15 years.
Galligan kicked a 58-metre free late in extra time as Cavan won by a single point.
Galligan top scored with four points from placed balls as Cavan claimed their second successive league title.
[25] On 24 July 2023, it was reported that Galligan was named as one of three people shortlisted for the Cavan manager's position to replace the outgoing Mickey Graham.