George Murray is Lord Grantham's lawyer and close confidant. He handles all the legal affairs of the family.
He found the new heir, Matthew Crawley, after the death of Patrick Crawley. During the war, when a wounded officer claimed to be Patrick, Robert wrote to him, asking him to check on the officer's story.
Robert then visited him in London, where Murray informed him that his railway investment had resulted in a severe monetary loss, enough for Downton to go. Robert told Murray he refused to give in.
Matthew later spoke to Murray about planning for the future of Downton, which he said was "music to my ears" because, as he explained, hard times were coming for estates like Downton and most families would fall, and that it would be good for Downton to run a business. Unfortunately Mary caught them and was upset they were discussing this matter because it was the same day Sybil's body was taken away.
Murray then worked with Anna to free her husband. He went to Audrey Bartlett after Anna visited her and found evidence to free him. Unfortunately Bartlett denied this to Murray, after having been tipped off, most likely from Durrant who, along with Craig, had overheard Murray talking to Bates and mentioning Mrs. Bartlett's name. He, Anna, and Bates discussed what to do next. He felt it would be guilt to lie to the law, and she might be swayed to telling the truth.
When Matthew addressed his plans again to Robert and Jarvis, Murray supported Matthew, pointing out that "the past is not much of a model." He cited the third earl nearly going bankrupt, the fourth only saving the estate by dying, and that they would have been in trouble in the 1890's had it not been for Cora's money.
In 1922, Robert contacts Murray following the discovery of Matthew's letter in which he expresses his intention to name Mary his sole heiress, in order to establish the legality of this letter.
After Anna is accused of murdering the man who raped her, Alex Green, Murray is called to stand for her. The prosecution learns that Anna had attacked her stepfather, who sexually abused her, with a knife, and explains that they intend to use it with the current accusation to establish a pattern and prove it would not be against Anna's nature to attack Green. But he hopes that he can find a way to rule the earlier incident as inadmissable in order to undermine the prosecution's case. Unfortunately he admits to Bates that the prosecution's case is very strong, and after a date is set for Anna's trial, Bates claims he did it and runs off in order to get her out of prison.
Murray is able to get her released from jail, and when Molesley and Baxter find a witness who puts Bates in York at the time of Green's death he is certain Bates will not be prosecuted once the statement is in. He also informs Lord Grantham that they will leave Anna at liberty for the time because the witness who previously identified her as being near Green before he died is having doubts now that it was her.