John Ronald Craigie Aitchison CBE RSA RA (13 January 1926 – 21 December 2009) was a Scottish painter.

[1] He was best known for his many paintings of the Crucifixion,[2] one of which hangs behind the altar in the chapter house of Liverpool Cathedral,[3] Italian landscapes, and portraits (mainly of black men, or of dogs).

His simple style with bright, childlike colours defied description, and was compared to the Scottish Colourists, primitivists or naive artists, although Brian Sewell dismissed him as "a painter of too considered trifles".

[1] His career-long fascination with the crucifixion was triggered by a visit to see Salvador Dalí's Christ of St John of the Cross in 1951 after it was acquired by the Kelvingrove Gallery.

Aitchison was educated at Loretto School, Musselburgh, East Lothian until the death of his father in 1941 and then at home by private tutors.

He returned to Edinburgh in 1950 to practise painting in a converted mews house in Church Lane, and then studied at the Slade School of Fine Art in London from 1952 to 1954 under William Coldstream and Robert Medley.

Fellow students included Michael Andrews, Tony Pacitti, Philip Sutton, Victor Willing, Paula Rego, Myles Murphy and Euan Uglow.

[10] In 1996 he was commissioned to paint a mural of Calvary – a landscape illuminated by a mystical light – for the Gothic Revivalist Truro Cathedral in Cornwall.