Liam is Frank Matthews best friend, Liam is a loyal and good friend towards him. He is normally seen comforting other kids in The Dumping Ground whether he is close to them or not. But he has shown on numerous occasions to be very hot-headed, especially when it comes to Mike or the police. Liam is normally the first to make sarcastic comments and jokes about others, mainly the adults. He has had five foster parents in the past, but he either refused them or scared them away.
Liam has one elder brother Jack O'Donovan who he first meets in series 3 episode 4 "Big Brother" at the end of the episode he goes to live with him.
In series 1 Liam is the artful dodger of Elmtree House. He was always getting into trouble with Frank, especially over his invention of Liamade. He was not shown to have many special relationships with others. He was closest to Frank and Tracy, and occasionally Carmen (Viva Carmen). He occasionally falls out with Johnny at times.
At the start of series 2, The Dumping Ground is being closed down and they are going to be transferred to Burnywood. Liam has been here before and doesnt want the others to have to go there. He trys to be the leader and try save the home. He sells everything in the home, then he has to buy it all back because Mike Milligan told him he had to.