Mariah Carey posted a pic of her snuggling up with husband Nick Cannon accompanied with:"There is only one forever, Happy Valentine's Day to all the lambs! Love always, Mariah and Nick."
The mum-of-two did make reference to the sadness she is feeling over the death of her friend Whitney Houston.
"A bittersweet Valentine's day... I hope everyone can share today with their loved ones!" she said.
David Hasselhoff's Welsh girlfriend Hayley Roberts wasn't able to follow Mariah's advice, however.
She tweeted to the former Baywatch star: "I love you very much... can't believe our first Valentine's Day together and we are apart."
Pop star-turned-new mother Lily Allen – married to painter and decorator Sam Cooper – wrote: "I love my husband x"
Lindsay Lohan was being more coy about who was the object of her affections, however, writing: "Yay!!! I have a Valentine!!!!!"
Pixie Lott's model boyfriend Oliver Cheshire posted a pic of the Valentine's breakfast - complete with red rose - he had prepared for his pop star love (above).
Comedian James Corden, who became a father last year, wrote to his fans: "Happy Valentines Day. Let's snuggle smooch and spoon all day! X"
TV host Davina McCall, who is married to former Pet Rescue presenter Matthew Robertson, said: "Happy Valentine's Day.
"(Matthew) and I do not celebrate as we try and make every day Valentine's Day. Doesn't always work but we give it our best shot."
Presenter and actress Denise Van Outen said she and her husband, West End star Lee Mead, had celebrated a day early.
"Just had a lovely Valentine's meal with my hubby. He is working tomorrow eve, not possible to go out then."
Presenter Myleene Klass, who married long-term boyfriend Graham Quinn in a secret ceremony last year, wrote: "Having an anti Valentine's Day. Think it should be every day. Er good luck with that!"