Lomas has a four-year-old son named Billy with his former girlfriend, Haley Lever. He and Coronation Street star Kym Marsh publicly announced their relationship in July 2008. In December 2008, Lomas and Marsh announced they were expecting a baby together, due in the summer of 2009. On 12 February 2009, Marsh released a statement on behalf of the couple, announcing their son, Archie Jay Lomas, had been born 18 weeks early on 11 February, and had died moments after birth. Marsh stated "Archie is our beautiful angel and we will miss him so much. Thank you all for your support."

He is the brother of Kelly and Cassie Lomas and half-brother of fellow soap actor Charley Webb, who plays Debbie Dingle and Danny Webb, who played Aaron Livesy in Emmerdale.

He is close friends with co-stars Hannah Tointon, Roxanne McKee, Ashley Taylor Dawson, James McKenna, Nick Pickard, Leah Hackett, Ricky Whittle, Darren John Langford and Anthony Quinlan. He still keeps in touch with many of his Dream Team co-stars.

Kym Marsh and Jamie Lomas announced their split, and on the 8 October 2009 Lomas moved out of Marsh's home. They were confirmed to have reconciled on 4 November 2009. Soon after on 25 December 2009 Jamie proposed to Kym and they are now engaged to be married in Crewe Hall in 2010. Jamie played a role of Brookworld

Nominated for Villain of the Year and Best Actor at the British Soap Awards 2007, 2008 and 2009. As well as this he was also nominated for Sexiest Male in 2007 and 2008. Lomas along with Gemma Bissix, Hannah Tointon and Chris Fountain picked up the award for Most Spectacular scene in 2008 for Clare Devine driving off a cliff.