Their new daughter weighs in at 4.16kg (9lbs 3oz) and was born yesterday at Stroud Maternity Unit.
The equestrian champ, 36, and former England rugby player, 39, are already parents to a four-year-old daughter named Mia.
The new bub, whose name is yet to be announced, will be the fourth grandchild of Princess Anne, Zara's mother.
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A statement released by the palace confirmed the happy baby news, everyone in the family is "delighted".
"The Queen, The Duke of Edinburgh, The Princess Royal, Captain Mark Phillips and Mike's parents, Mr Philip and Mrs Linda Tindall, have been informed and are delighted with the news," the statement read.
"The baby's name will be confirmed in due course."
On Christmas Eve last year, Zara and Mike made the devastating announcement they had lost their second child.
It's believed Zara was about four months into her pregnancy.
"Very sadly, Zara and Mike Tindall have lost their baby. At this difficult time, we ask that everyone respects their privacy," a rep for the couple said at the time.
Speaking about their loss in May, Mike revealed little Mia had been their "saving grace."
"One thing you do learn is how many other people have had to go through the same," Mike told the Sunday Times.
"The saving grace for us has been Mia, our daughter who is now three. However down we feel she will come running up in our faces," Mike continued.
Our congratulations and good wishes are with the new family of four.