The 21-year-old midfielder had been on the books of the Hoops from 2009, but the youngster could play just once in the Scottish Premiership.
Following loan spells at Dumbarton, Queen of the South (twice) and Livingston. Thomson was released by Celtic this summer, and he has moved to Dunfermline.
The youngster has stated that he is not disappointed at leaving Celtic, and that he had know for a while that his time at Celtic Park was coming to an end.
Thomson told Capital City Press: “That was my contract up at Celtic and I had known for a couple of months.
“I didn’t get told until late in the season that that was going to be me at Celtic, but I’m looking forward to the season ahead with Dunfermline now.
“I’d be lying if I said I was disappointed to be leaving Celtic, because I wasn’t. I didn’t want to go back and be playing youth team football, I wanted to challenge myself.”
Away from Celtic
Competition for places in the Celtic team is fierce, and it was always going to be hard for Thomson to break into Brendan Rodgers’s first team.
Young and talented players like Thomson need to play competitive football on a regular basis, and the 21-year-old Scotsman will hope that he does well for Dunfermline in the Scottish Championship.