Associação Desportiva Sanjoanense was founded on 25 February 1924 in São João da Madeira, district of Aveiro, and plays at the Estádio Conde Dias Garcia. In 2024-25 it competed in Liga 3, the third tier of Portuguese football, where it has played since 2021-22. Its honours include four national Segunda Divisão titles, in 1965-66, 1998-99, 2000-01 and 2003-04.