Robert Knott Blessley (1833–1923) was a British architect based in Eastbourne, East Sussex.
After training as an architect he set up an office in Furnival's Inn, London before moving to Eastbourne by 1866.
During his time in Eastbourne he was responsible for the design of several local developments, including the Grand Hotel and the Leaf Hall.
In the absence of a local theatre the hall was used for staging visiting shows, including General Tom Thumb in 1865.
It now serves as a community arts centre and is a grade II listed building.