Roy Lancaster, OBE (born 1937) is a British gardener and broadcaster.
Charles Roy Lancaster was born in Farnworth, Lancashire and best known for his work on the long running BBC TV programme, Gardeners' World. He has also regularly appeared on the BBC Radio show Gardeners' Question Time and is also a freelance writer and lecturer.
Formerly the first Curator of the Hillier Arboretum (now the Sir Harold Hillier Gardens), he has travelled the world on plant finding expeditions but is also busy in the UK. He has been a member of the Royal Horticultural Society for almost 40 years, and is vice-chairman of the society's Floral Committee B and a member of several other committees. Mr Lancaster is also President of the Hardy Plant Society; a UK based horticultural society that fosters interest in hardy herbaceous plants.
In 1988 he was awarded the Victoria Medal of Honour and in the 1999 New Year Honours he was awarded an OBE for services to horticulture.
The standard author abbreviation Lancaster is used to indicate this individual as the author when citing a botanical name.