The Laurence Olivier Award for Best Actor in a Musical is an annual award presented by the Society of London Theatre in recognition of achievements in commercial London theatre.

The awards were established as the Society of West End Theatre Awards in 1976, and renamed in 1984 in honour of English actor and director Laurence Olivier.

This award was introduced in 1979, along with the award for Best Actress in a Musical.

In 1977 and 1978, there had been a commingled actor/actress award for Best Performance in a Musical, won both times by an actress.