Sir Isaac Bayley Balfour, KBE, FRS, FRSE was a Scottish botanist. He was Regius Professor of Botany at the University of Glasgow from 1879 to 1885, Sherardian Professor of Botany at the University of Oxford from 1884 to 1888, and Professor of Botany at the University of Edinburgh from 1888 to 1922.

John Hutton Balfour was a Scottish botanist. Balfour became a Professor of Botany, first at the University of Glasgow in 1841, moving to the University of Edinburgh and also becoming the 7th Regius Keeper of the Royal Botanic Garden Edinburgh and Her Majesty's Botanist in 1845. He held these posts until his retirement in 1879. He was nicknamed Woody Fibre.