The award caps a memorable end to the season for the former Norwich and Northern Ireland manager, who steered York to safety after replacing the sacked Gary Mills at Bootham Cresecent in March.
The Minstermen were one of eight clubs who could have fallen out of the Football League when Worthington took charge, but a run of four wins and two draws in their last six matches ensured their survival.
"I'm obviously delighted to receive this award," Worthington told Press Association Sport.
"I've picked it up on behalf of everyone involved at the club. It was a real team effort and it's fully deserved, no more so than by the players and supporters, who between them helped ensure York City stayed in the Football League.
"We came in with 10 games to go and there was a bit of work to be done and it had to be done quickly.
"The players must take most of the credit because they did exactly what they were asked to do.
"That was important and throughout the run-in, by sticking together and working very hard we got some very, very good results."
Captain Chris Smith made it a clean sweep for York by collecting the player of the month gong.