PC Andy Davidson is Gwen Cooper's former police partner, first appearing in "Everything Changes". He finds glamorous police programmes like CSI: Crime Scene Investigation ridiculous and also seemed to be somewhat put out by Gwen's more inquisitive nature.
After Gwen joins Torchwood, she meets him again outside a nightclub where a man has been killed by a "sex monster"-possessed host in "Day One". Like Gwen's boyfriend Rhys Williams, he believes that she has been promoted to "Special Ops".
PC Andy returns in "End of Days", requesting Gwen's help after a Roman soldier has fallen through time only to murder two men and subsequently be arrested. Jack and Gwen talk very frankly about what has happened in front of him.
In the second series debut, Kiss Kiss, Bang Bang, he is present after a man is killed by Time Agent John Hart.
In "Adrift", Andy assists Gwen with her investigation of a sudden disappearance. During this, he reveals his affection for her and jealousy toward Rhys, which Gwen discovers to be his excuse for not attending her wedding in Something Borrowed. It is revealed he still has a soft spot for Gwen and has a childish crush on her.
Gwen and Andy meet in the novel Another Life at the scene of Guy Wildman's death. He also features in a flashback in the novel Trace Memory.
