Hearn tweeted the confirmation of the much-anticipated world heavyweight fight, which will be held at the Principality Stadium in Cardiff.
Parker himself is looking to extend his own undefeated streak, with the WBO Heavyweight champion now 24-0 in his professional career, coming off a successful defence of his Heavyweight championship against Hughie Fury at Manchester Arena in September.
Parker said: "Anthony Joshua is in for a huge shock. A couple of months ago I heard him say 'why should I be anxious about this little kid from New Zealand"?
Joshua unified the WBA and IBF titles with his famous win over Wladimir Klitschko last April, before subsequently battling out a late stoppage win over Carlos Takam in Cardiff in October.
GETTY IMAGES Joseph Parker's pre-fight approach has Anthony Joshua riled
"Well, now he's about to find out, and the world is about to find out whether AJ can really take a punch".
"Eddie has been great to work with from day one", Higgins said. My promoters are focused on what they have to do and I know what I have to do - train hard, be mentally strong, be in great shape and put in a great performance.
Anthony Joshua will enter the fight as the favourite.
"Joseph Parker is the absolute epitome of the Kiwi sporting battler". He's consistently fought fighters in the world's top ten and he's beaten them all easily. Afterwards it was a case of "when" not "if" boxing would return and we are thrilled to be working with Matchroom once again to raise the bar for live boxing entertainment on March 31st. "2018 is set to be yet another exciting chapter in the stadium's illustrious history!"
An announcement on on-sale dates, ticket prices and travel packages will be made soon.