The actor's wife Samantha Sharp yesterday gave birth to a daughter, who the couple have named Sophia Melody. The baby weighed in at 7lb 7oz.
Thomson and Sharp, who tied the knot in 2005, already have a 7-year-old daughter named Olivia together.
Speaking of the new arrival, Thomson confirmed: "All three of us - Sam, Olivia and I - are absolutely made up."
In September last year, the soap star announced that he and Sharp had conceived naturally following three unsuccessful attempts at IVF treatment.
Thomson recently bowed out from his role as Weatherfield's Jesse Chadwick.