The Shrimps’ boss had been shortlisted after their 10-point haul which saw them preserve their place in the third tier, finishing two points clear of the relegation zone.
However, the prize was won by Wycombe Wanderers’ manager Gareth Ainsworth after they picked up 17 points from seven matches to clinch a play-off position.
Ainsworth said: “April was a massive month for us, particularly with us coming back after a two-week international break and hoping to carry on momentum from a good run of results in March.
“The boys were brilliant in every department and it was a fantastic achievement for us to break into the top six, particularly with lots of teams around us picking up good results as well.
“I’m delighted to win the Sky Bet League One Manager of the Month award, which is testament to the hard work and focus of everyone at the training ground, including all the players and staff.”
The judging panel was chaired by Danny Wilson, who added: “Gareth’s Wycombe sprinted through April and snatched a play-off place with a 17-point return after seven unbeaten games.
“Wins against play-off rivals Sheffield Wednesday and Plymouth enabled them to catapult into the top six on the final day of the season.”
Also nominated were Alex Neil, whose Sunderland team face Wycombe in the promotion-play-off final a week tomorrow, and Sheffield Wednesday boss Darren Moore whose players lost to Sunderland in the semi-final.