William Hastie Geissler (1894 Edinburgh - 1963) was a Scottish artist known for his watercolours of the natural world. He was one of the Edinburgh School, and much of his earlier work came from sketching trips undertaken with other members of this group, though he himself is sometimes described as a "neglected" member.
Geissler and William Gillies both graduated from Edinburgh College of Art in 1922, having won scholarships, and exhibited for several years with colleagues as The 1922 Group. Some exhibitions included work by William MacTaggart, John Maxwell and William Crozier. In 1924 Geissler, Gillies and Crozier travelled to Paris to study with André Lhote.
Geissler tutored at the College of Art in the 1920s before a spell teaching at Perth Academy. In 1931 he married Alison McDonald, later known as the glass engraver Alison Geissler, and took a post teaching art at Moray House in 1935. He was a member of the Society of Scottish Artists (SSA) and of the Royal Scottish Society of Painters in Watercolour (RSW).
His works include: