The Three Lions talisman celebrated the arrival of baby girl Lillie Saint with his childhood sweetheart fiancée Fern Hawkins.
Maguire, 26, took to social media to reveal the news, posting an adorable picture of himself holding the hand of his newborn on Instagram, captioned: “Welcome Lillie Saint Maguire.”
Fellow professionals offered their congratulations, including Liverpool’s Jordan Henderson and his Leicester City team-mates Ben Chilwell and James Maddison.
The Sheffield-born central defender’s most recent international partner, Everton’s Michael Keane, commented: “Congratulations mate.”
West Ham starlet Declan Rice said: “Congrats mate,” while Fulham midfielder Kevin McDonald added: “Congratulations big man.”
Proud dad Harry replied: “Thanks everyone. Both Fern and Lillie doing great.”
Stunning Fern, 24, who had kept the pregnancy under wraps, shared the same heart-warming photo to her personal Instagram account.
She wrote: “A little project I have been working on for the past 9 months.
“Lillie Saint Maguire, you have stolen our hearts you precious angel.”
Nine months ago, Harry and Fern were snapped in an iconic picture taken after the famous shoot-out win over Colombia.
And it seems the celebrations went long into the night.
The Foxes’ centre-back also went on to score in England’s World Cup quarter-final triumph over Sweden.