Will Oscroft, director of Ogilvy Action Sports and Entertainment, will join the consumer shop as head of sport on 7 September.
Oscroft takes charge of a ten-strong team and will sit on the Lexis board. He will look at ways of widening the remit of the agency's sports offering.
He replaces Guy Pattison, who is taking a year-long travel break, following an eight-year stint at the agency.
Oscroft has been at Ogilvy since 2002 and currently works on American International Group's four-year £56.5m relationship with Manchester United - the biggest shirt sponsorship deal in English football.
Previously, Oscroft was a director at Marketing Activity, Volvo's sponsorship agency, and an account manager at Ketchum Sponsorship.
Lexis Sport clients include the Barclays Premier League, the Rugby Football Union and EDF Energy. Some of the EDF Energy account team are currently in Beijing for the start of the Olympics.
Separately, Lexis has won a six-figure account to launch a US social shopping site called ShopStyle. The account will be headed by director Chris Cook