Søren Lerby (born 1 February 1958) is a Danish former football player, manager, and licensed agent. As a player, he spent the bulk of his career in Dutch football, winning five Eredivisie championships with Ajax Amsterdam as well as the 1988 European Cup and two further Eredivise titles with PSV Eindhoven. He also won two Fußball-Bundesliga titles with Bayern Munich, and played one season for AS Monaco in France. He played 67 matches for the Denmark national football team from 1978 to 1989, and represented Denmark at the 1986 FIFA World Cup and two European Championship tournaments.

A left-footed midfielder, Lerby was a player who was always committed and a leader of the team. His commitment is testamented by the fact he chose to play two competitive matches in two different countries on a single day on 13 November 1985. First in the afternoon a World Cup qualifier with Denmark in Republic of Ireland, later in the evening a DFB-Pokal match with Bayern Munich against VfL Bochum.

Lerby always played with his "socks down" – short socks or long socks rolled down but always without shin pads. This was quite uncommon of the day and would be illegal today.