The 32-year-old singer and TV presenter shared the news with her fans on Twitter, posting: 'Justin and I are so happy to let you all know we are having a baby!!! Couldn't wait to share our lovely news with you all'.
Justin and I are so happy to let you all know we are having a baby!!! Couldn't wait to share our lovely news with you all 👶🍼 ❤️
- Kimberley Walsh (@KimberleyJWalsh) February 24, 2014
Congratulations immediately began pouring in, with Hello! and OK among some of the first to tweet their best wishes.
Huge congratulations to @KimberleyJWalsh! Amazing news! Lots of love. x
- OK! Magazine (@OK_Magazine) February 24, 2014
Walsh has been with partner Justin Scott, formerly of hip-hop boyband Triple 8, for a decade but the two are in no hurry to tie the knot. Last year she told BBC Three chat show Staying in with Greg and Russell: "We're not too bothered about the whole marriage thing.
"It's still pretty good after 10 years.We try to keep the fire alive. You do different things for each other after 10 years, you know if you get in and have a bath run with candles, I'm happy with that."
The news comes hot on the heels of bandmate Nadine Coyle's announcement that she had given birth to a little girl on February 10.
Coyle also took to Twitter to share the news, tweeting: 'I am overjoyed to let you know our little girl is here. She is amazing! I love being a mammy & will fill you all in soon. Love Nadine Xx'.
I am overjoyed to let you know our little girl is here. She is amazing! I love being a mammy & will fill you all in soon. Love Nadine Xx
- Nadine Coyle (@NadineCoyleNow) February 10, 2014
Kimberley has previously stated that she is keen to try a natural birth, although after being present at the birth of her nephew she added: 'after seeing it, I can see why most celebs opt for a caesarean!'.