The season began on 26 September 2017, and ended in May 2018, with a mid-season break while Victoria Stadium underwent improvements.

Gibraltar Phoenix were the reigning champions, having won the league for the first time the previous season and earning promotion to the Premier Division.

On 2 February 2018, Angels were expelled from the league due to violations of squad quota and Home Grown Player rules, with their record expunged.

Europa Pegasus had applied to join the division for the coming season after their expulsion at the end of the 2015–16 season, but the Gibraltar Football Association turned down their request, citing new rules now forbidding feeder clubs from joining the Gibraltar football pyramid.

1 Norberto Alonso Simón was re-appointed by Leo in January after initially being dismissed by the new owners.