Lady Gaga was among the stars wishing crooner Tony Bennett a happy 94th birthday.

The I Left My Heart In San Francisco singer marked the milestone on Monday and his famous friends were on hand to pay tribute.

Gaga, 34, is a close friend of Bennett and the pair collaborated on the 2014 album Cheek To Cheek.

She shared a picture of the pair together and wrote: “You hold such a special place in my heart. Whenever I think of you I always Smile, just like Charlie Chaplin wrote.

“You’re beautiful inside and out and the whole world loves you. I celebrate you today from home. But I wish we were Cheek to Cheek.”

A message on Bennett’s official Twitter account had earlier asked fans to send the star happy birthday messages and the theme of the day was The Best Is Yet To Come, one of the songs he is associated with.

Sir Elton John was among those to oblige. He shared a video message to “an amazing man, an amazing artist,” telling Bennett “you get younger every year”.

Sir Elton added: “At the moment we’re going through some hard times but you and I have probably been through worse times than what we’re going through.

“And you and I are always optimists, and artists usually are. So, I’m hoping next year, things will completely turn around and people like you and I can go back to work and entertain people and spread joy and love throughout the world, which it desperately needs at the moment.”

Billy Joel was another sending Bennett best wishes. He tweeted: “Thank you for bringing the songs I wrote to such glorious life. Happy Birthday.”

Elvis Costello shared a picture of him and Bennett and said: “You have made the world a better place and we will sit like this again, one day. You are the best and #TheBestIsYetToCome With much affection and respect. Elvis Costello.”

Sting described Bennett as “truly an inspiration”, Stevie Wonder praised the singer for his support of the civil rights movement and Andrea Bocelli serenaded Bennett with a rendition of happy birthday.