[1] The Premier Division consists of 20 clubs, the same as last season, after Street and Melksham Town were promoted to Southern League Division One South & West, and Longwell Green Sports and Wells City were relegated to the First Division.
Four new clubs joined: The First Division consists of 20 clubs, reduced from 22 the previous season, after Roman Glass St George and Westbury United were promoted to the Premier Division, and Almondsbury and Malmesbury Victoria were transferred to the Hellenic League Division One West.
Two new clubs joined: Preliminary Round ties were played from 25 September until 2 October 2018.
December Third Round ties were played from 26 November 2019 until 22 January 2020.
The 2018/19 Les Phillips Cup Final was played at a neutral venue.