Jessica and her husband Andy Hill "couldn't be happier" as they welcomed their first child together yesterday (17 July).
Taking to Twitter this morning, the Olympic champion posted a very cute picture of her son, Reggie Ennis-Hill, to confirm her special news.
Alongside the adorable photo of her newborn, Jessica said: "Our beautiful baby boy Reggie Ennis-Hill was born yesterday. We couldn't be happier x."
Earlier this year in January, Jessica and Andy announced they were expecting their first child together.
In their statement Jessica revealed her pregnancy had taken both her and her husband by surprise.
She said: "I have some very unexpected but exciting news to share – Andy and I are expecting a baby. We are completely overwhelmed, with excitement and a degree of anxiety that I am sure all first time parents will relate to."
As a result of her pregnancy, Jessica announced she will not compete in the 2014 Commonwealth Games starting in Glasgow next week as her priority is now her baby boy.
However, the athletic star has said she plans to return to full time athletics in her bid for gold at the Rio Olympics in 2016.
Childhood sweethearts, Jessica and Andy married in May 2013 after eight years together.
Congratulations on the arrival of your little Ennis-Hill!
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Stars who welcomed babies in 2014 in pictures:
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