The Hollyoaks actor has been waiting on tenterhooks for the last week after Karen surpassed her due date without going into labour.
Ashley took to the Strictly dance floor for the first time on Friday night (27 September) and admitted that he kept running backstage to check his mobile just in case!
Thankfully, the proud dad made it to the hospital this morning and was able to hold Karen's hand as she gave birth to Mason.
Announcing their exciting news on Twitter, Ashley has tweeted: "My hero @karenmckay1 gave birth to our 2nd little dream Mason Mac Taylor Dawson this morning!!
"Thx for all the support. We are thrilled XXX"
Ashley - who plays Darren Osborne in Hollyoaks - and Karen are already parents to two-year-old Buddy Mac Taylor Dawson.
Congratulations! No doubt Ashley will have an extra spring in his step next time he appears on Strictly!
See who else has welcomed a baby into the world this year in our gallery:
Copyright: Love & Lust London