Johnson saw off the challenge of three rivals to win the backing of the Tories in the safe seat of Uxbridge and South Ruislip.
Johnson won on the first count following a behind-closed doors pitch at a local school hall, during which he was expected to address concerns over his plans to see out his mayoral term, which runs until 2016, while potentially serving in parliament.
Many see the 50-year-old, known for his unkempt shock of blond hair and frequent gaffes, as a potential successor to Conservative Prime Minister David Cameron, given his high profile and popularity with grassroots party members.
The first step to this goal -- a return to parliament -- looks virtually assured, with the Conservatives having held the seat since 1970.
Johnson revealed last month that he wanted to return to the House of Commons, where he sat as a lawmaker between 2001 and 2008.
The Uxbridge and South Ruislip seat is currently held by Conservative lawmaker John Randall, but he announced in July that he would not be seeking re-election.
