The actor, who plays builder Jason Grimshaw in the ITV1 soap, has been dating the woman for a few weeks, but wants to take things slowly, according to The People.
The pair were attending Jack P Shepherd's engagement party at the Great John Street Hotel in Manchester alongside other Coronation Street stars such as Samia Smith (Maria Connor) and Will Thorp (Chris Gray), who have been seeing each other since January.
Sam Aston (Chesney Brown) arrived with his first girlfriend and Mikey North (Gary Windass) also took his girlfriend, believed to be a 21-year-old student called Katy.
Thomas recently admitted that he loves being a dad to daughter Scarlett, describing her as his number one responsibility.
Co-star Shepherd got engaged to long-term girlfriend Lauren Shippey back in April, shortly after Sammy Milewski gave birth to Shepherd's son following a one-night stand with him last year.