The Mid Wales South League was an association football league, from Mid Wales but some from just over the border in England. It was last called the Watson Financial Mid Wales League (South) for sponsorship reasons. The founder members of the league were Brecon St John's, Felindre, Llandrindod Wells, Llanwrthwl, Llanwrtyd, Presteigne St. Andrew's, Rhayader Town and Whitton. Felindre were the first league champions. The league last operated in the fifth level of the Welsh football league system. Teams were eligible to be promoted to the Mid Wales Football League if standards and facilities fall into line with the regulations of the Mid Wales League. There was no league directly below the South League. The league was sometimes written as the "Mid-Wales League (South)". In the 2019–20 season, when the season was curtailed due to the coronavirus pandemic, Brecon Corries were champions with a 100% record of 16 wins from 16 games with 143 goals scored and just two conceded. In addition to these statistics the team scored a 27–0 win at Knighton Town Reserves which was expunged from the record books following Knighton’s withdrawal from the league. The final season of the league, 2022–23 saw only five clubs compete in the league.

Member clubs for 2022–23 season

Champions

1960s

1970s

1980s

1990s

2000s

2010s

2020s

Number of titles by winning clubs