Ackworth School John Gilbert Baker FRS (13 January 1834 – 16 August 1920) was an English botanist.

He wrote handbooks on many plant groups, including Amaryllidaceae, Bromeliaceae, Iridaceae, Liliaceae, and ferns.

His published works include Flora of Mauritius and the Seychelles (1877) and Handbook of the Irideae (1892).

[9] He was awarded the Veitch Memorial Medal of the Royal Horticultural Society in 1907.

Several plant species with the epithet bakeriana or bakeranius and bakeranium have been named in honour of John G.