The couple took to Instagram to share the news, both sharing a snap of them smiling and holding a photo of a scan with Wes clutching a karate-themed baby grow.
"Happy early Christmas from our family to yours,” he captioned the photo.
"A new little warrior added to the clan. We can’t wait to meet you and here’s to the next chapter together.”
Wes plays Doug Ferguson on the hit soap, with his Fair City co-stars congratulating the couple in the comment section.
"Wow huge congratulations ! Delighted for you," wrote Stephanie Kelly.
"Massive congratulations brother. Absolutely delighted for both of you,” Dave O’Sullivan added while Rodrigo Ternevoy said: “Huge congratulations my friend, you’ll be an amazing father.”
Leanne also shared the same photos, saying she “couldn’t be more happy or excited to announce that we are expecting a beautiful, precious little baby.
"You are so loved already baba. Here is to the most amazing adventure with the most amazing person,” she wrote, tagging Wes in the caption.
The couple celebrated their first anniversary together in September, with loved-up Wes often sharing public insights into their relationship.
When RSVP asked him what his ‘best kiss’ was in June, Wes said: “This might be a bit mushy but definitely when my girlfriend told me she loved me too for the first time and kissed me afterwards.
"I felt like a little shy, happy kid, to be honest.”
Wes is just the latest of the Fair City family to announce he is a parent-to-be, with former star Jenny Dixon recently throwing a gender reveal party for her unborn twins.
The actress is expecting with her husband Tom Neville, an ex-TD for Fine Gael, and the pair announced the sex of the babies in style.
With a large white balloon between the loved-up couple, the soap star and her husband popped it with a pin, revealing a tumble of pink balloons to signify twin girls.
“We’ve waited a lifetime for this moment.. a surreal day. a beautiful one.. a thankful one. #GenderReveal what will our baby twins be!”
Jenny thanked everyone “for the love” in the “beautiful moment,” as stars like Rosanna Davison shared heart emojis and best wishes with the parents to be.
Jenny and Tom met at a film festival in Limerick in 2016, just as the long-term county councillor had been elected as a TD for Limerick.
“I didn’t actually know he was a politician when I met him, I just thought he was an aspiring actor,” she told The Irish Sun.
They married in 2019 in Dublin before celebrating with a lavish reception at Powerscourt Estate in Wicklow, a year after the TD proposed in Italy.
Celebrity guests included Jenny’s Fair City co-stars George McMahon, Bryan McMahon and Una Crawford O’Brien as well as Tom’s Fine Gael colleagues like Leo Varadkar.