Andy Murray is celebrating becoming a father after his wife Kim Sears gave birth to a girl.
The Dunblane tennis star's partner is understood to have given birth on Sunday night, the BBC reported.
Andy's mother Judy appeared to confirm the news in a light-hearted Twitter exchange with Scots stand-up comedian Fred MacAulay.
In a message to Judy, the comedian wrote: "Delighted to hear Andy And Kim Murray's lovely news. @judmoo ... surely a cert for 2016 GlamGran comp at Butlins."
Judy replied: "Love it."
Other well-known names from the worlds of sport and politics have offered the couple - who married last year - their congratulations.
Scotland's First Minister Nicola Sturgeon tweeted: "Lovely news. Congratulations to @andy_murray and Kim on the birth of their daughter. Wishing every happiness."
Former British number one tennis star Annabel Croft, paralympic wheelchair tennis player Lucy Shuker, former Olympic champion Sally Gunnell and Olympic skeleton champion Amy Williams also sent early congratulations to the couple.
Andy's grandmother Shirley Erskine told the BBC she was thrilled at the arrival of the new addition to the family.
Sports bodies British Tennis, Team Scotland and the Davis Cup sent their best wishes to the new parents.
Sports broadcaster Gabby Logan said: "Kim and Andy Murray have had a baby girl - huge congrats." And in a note to Murray's mother Judy, the presenter added: "@judmoo - great news for Fed Cup team 2036."
Scottish Labour leader Kezia Dugdale also voiced joy at the development, saying: "It's a girl! Huge congratulations to Kim Sears and @andy_murray on their wonderful news."
Hundreds of messages of support for the family have also been posted online from members of the public.
The birth of the couple's first child comes after a momentous 12-month period for Murray, the British number one and a double grand slam winner.
The long-term couple, who live in Surrey and are both 28, married in Murray's home town of Dunblane in April last year, cheered on by a large crowd of well-wishers.
Kim's pregnancy was confirmed publicly in August after they had told family and friends the news, following the 12-week scan.
Murray spoke ahead of the Australian Open about the upcoming birth.
"Just now it's a big change coming. It's very, very exciting," he said.
The Scot made it clear in January that he would have cut short his first grand slam of the year and flown home if the baby had arrived earlier than expected.
Confirming he would even have quit the tournament with one match left to play, he added: "For me, my child is more important to me, and my wife is more important to me than a tennis match.''
Murray did make it to the final and tearfully told Kim he would be on "the next flight home" after being beaten to the title by Novak Djokovic.
Speaking to the crowd after the defeat, Murray gave a message to Kim, who was ''watching back home''.
He said: ''You have been a legend the last two weeks, thank you so much for all of your support. I'll be on the next flight home.''
On the tennis court in 2015, Murray reached the semi-finals of the French Open and Wimbledon, and won his first titles on clay.
He rounded off the year by steering Great Britain to its first Davis Cup title in almost 80 years. He was also crowned BBC Sports Personality Of The Year for a second time.
As well as making it to the 2016 Australian Open final, he watched his brother Jamie become the first Briton to win the Australian Open men's doubles title in more than 80 years.
Judy has said she will be taking a step back from tennis to focus on her new grandchild.
She said she would make the newborn a priority in her life after missing out on important family moments because of her coaching career.
The 56-year-old told Hello magazine she was really looking forward to being a grandmother.
She said: "I shall be an active granny. My mum Shirley was very involved with Jamie and Andy when they were growing up and I hope to be the same with my grandchild."
Despite encouraging Andy's talents in the sport, she said she will leave teaching tennis to the new arrival to the baby's father, currently ranked second in the world.
"Children can start playing tennis with mini racquets from the age of three but I don't think I could go through all that nurturing of talent again.
"It takes years of dedication and sacrifice, and now I just want to enjoy time with my family," she said.
Mrs Erskine said the family had not known what sex the baby was going to be.
She told BBC Scotland: "Andy and Kim said from the outset that they didn't want to know, so I'm assuming that they didn't know and of course none of us knew, so it was nice to get a little surprise like that."
Mrs Erskine, Judy's mother, said she received a text message from Andy telling her about the birth.
"Andy had sent a text round all the family - one of these multi media type texts - and then I got a text from him saying something about 'she's doing well' and I thought 'oh something's happened'," she told the broadcaster.
She said there was no name yet for the baby but that she was "doing well", and voiced hope the couple would head to Scotland with their new baby.