The 1956–57 season was Colchester United's 15th season in their history and their seventh season in the Third Division South, the third tier of English football. Alongside competing in the Third Division South, the club also participated in the FA Cup in which the club were eliminated by Southend United in the first round in the first Essex derby in a cup competition. The season would be Colchester United's highest league finish for 50 years by ending their campaign in third position. It has only been bettered on three occasions; the 2005–06 season, 2006–07 season and the 2007–08 season.