Benjamin Samuel Williams (2 March 1822 – 24 June 1890), English orchidologist and nurseryman in London, known mainly for his horticultural notes on orchids in publications such as The Orchid Grower's Manual (London 1852, 7th ed. 1894), Select Orchidaceous Plants (London 1862 onwards) and The Orchid Album (London 1882-97). This botanist is denoted by the author abbreviation B.S.Williams when citing a botanical name.