James Henry Baum (18 December 1878 – 20 February 1936), also known as Jimmie Baum, was a Scottish trade unionist and socialist activist. Born in Dalbeattie in Scotland, Baum's father died while working in a quarry while James was young, and he was instead brought up by his grandfather, in Mountsorrel in Leicestershire. His grandfather had been a Chartist, and this interest in radical politics led James to join the Independent Labour Party (ILP) in 1900. Baum died suddenly, while in a London hotel, in February 1936.