William Russell "Ross" Davidson (25 August 1949 – 16 October 2006) was a Scottish actor best known for his role as Andy O'Brien in the BBC soap opera EastEnders.

He also had small parts as a member of a mime troupe in The Comedy of Errors ("BBC Television Shakespeare", 1983) and a photographer in Widows II (1985), as well as appearing in the film The Pirates of Penzance (1983) and the Monty Python short The Crimson Permanent Assurance (1983), made to accompany the group's feature The Meaning of Life.

He played the altruistic nurse Andy O'Brien for 18 months, after which his screen alter-ego was the first main character to be killed off, dying in a road accident in August 1986.

[1] While he was working on EastEnders Davidson began a relationship with Shirley Cheriton, who played his on-screen girlfriend Debbie Wilkins.

It was unsuccessful and a month later he was readmitted to the Oldchurch Hospital in Romford, where he was told that he had a glioblastoma Grade 4, the fastest-growing and most invasive form of brain tumour.