Sir William Borlase's Grammar School Boat Club is a rowing club on the River Thames based at Longridge, Quarry Wood Road, Marlow. The club belongs to the Sir William Borlase's Grammar School.
The club was formed in 1921.
The club shared the boathouse facility at Longridge Activity Centre on Quarry Wood Road, with Great Marlow School Boat Club when the latter moved there in 2009.
From 2012 to 2015, the club won the prestigious Fawley Challenge Cup three times at the Henley Royal Regatta.
The facilities for rowing at the Longridge Outdoor Activity Centre were limited with boats being operated from outdoor racks, which led to a 20 year search at 15 locations before an application for a new boathouse was submitted at Gossmore Lane on the opposite side of the river. The facility called the Marlow and District Schools Boathouse is due to open in December 2025. The construction met with some controversy over using Green belt land to build the boathouse.
In 2025, the club won its first national title since 2017, at the 2025 British Rowing Club Championships.
Key= O Open, W Women, +coxed, -coxless, x sculls, J junior, 18 16 age group