In 1958 Corby transferred to the Southern League, spending their first season in the North-Western Division, before being placed in Division One for the 1959–60 season. Despite only finishing sixth in 1961–62, Corby applied for election to the Football League. However, they failed to receive a single vote. After finishing seventh the following season the club applied again, and again received no votes. In 1963–64 they reached the first round of the FA Cup for a second time, losing 3–1 at home to Bristol City. They appeared in the first round again the following season, losing 3–1 at home to Hartlepools United. The season also saw them finish fourth in Division One, earning promotion to the Premier Division, as well as making another failed bid for Football League membership.