Lenana School is a secondary school in Nairobi, Kenya. It was formed in 1949 by colonial governor Philip Euen Mitchell, known then as the Duke of York School, named after a British World War II 1939 King George V-class battleship. The bell from HMS Duke of York is mounted on a bell-shed bythe front school parade ground between the school chapel and the hall. The first students were briefly housed at the then-British colonial governor's house, which is the current State House as they waited for the school's completion. The founding principal was R. H. James.

The school was renamed Lenana School in 1969 after the central person in the conflict between British imperialists and the Maasai, the latter's spiritual leader Laibon Lenana. The first Kenyan principal of the school was James Kamunge. The referral to old students of the school changed from the phrase Old Yorkist to Laibons, the latter being a title given to religious figures of the Maasai.