Davidson started his working life as a
physical education teacher in
Scotland in the early 1970s. He also played water polo at international level for Scotland. He left teaching to run a pub and disco in
Glasgow, but furthered his ambitions to act by attending night classes. He made his screen acting debut on television in
A Degree of Uncertainty (1979), a BBC
Play for Today set in a Scottish university, then appeared as a kilted dancer in
Stanley Baxter on Television (1979). 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. In
Spain, the
Netherlands and
Germany he was seen in commercials for products ranging from chewing gum to beer. In 1985 he became one of the original cast of the BBC's flagship soap opera
EastEnders. 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. Just before he left
EastEnders Davidson recorded a pop single, "Jigsaw Puzzle", that failed to chart. He then returned to acting in stage plays (he had previously appeared in
Guys and Dolls at the
National Theatre) and returned to the small-screen in 1987 as a television presenter. He presented the BBC lunchtime magazine show
Daytime Live (1987–88) and the sports challenge series
Run the Gauntlet (1989–90). Davidson later returned to acting and appeared in the
Channel 4 soap opera
Brookside and in the Welsh soap
Pobol Y Cwm. He also played the role of Peter O'Dell in the Scottish soap
Take the High Road for three years. He starred as Andy Morgan in the
Channel 4 soap opera
Hollyoaks from 1999 to 2002. ==Personal life==