The 2012–13 Wessex Football League (known as the Sydenhams Football League (Wessex) for sponsorship reasons) was the 27th season of the Wessex Football League since its establishment in 1986.
Both divisions this season consisted of fewer teams than last season – the Premier Division had 21 teams and Division One had 16 teams.
The Premier Division featured 21 teams, reduced from 22 the previous season, after Winchester City were promoted to the Southern League, Laverstock & Ford were relegated to Division One, and Brading Town withdrew from the league.
Two new teams joined the Premier Division, both promoted from Division One: Division One featured 16 teams, reduced from 18 the previous season after AFC Portchester and Verwood Town were promoted to the Premier Division, and Warminster Town transferred to the Western League.
[12] One new team joined, relegated from the Premier Division: