The 23-year-old converted penalties in three successive games, earning the Mariners seven points over the month in their ultimately successful quest for safety.
Indeed, two of the spot kicks came in the final 10 minutes against relegation rivals Chesterfield and Barnet, testament to Rose's resolve under pressure.
"Mitch has really stepped forward this month, delivering under pressure with his three penalties and his overall performances," Grimsby boss Michael Jolley told the EFL site. "He was certainly pivotal to our improved form in April and fully deserves this recognition."
Rose, meanwhile, added: "I'm delighted, obviously it's a huge accolade to have from an individual perspective and I'm just happy to be able to finish the season on a high.
"The new manager brought a real work ethic into the group, the training intensity went up massively when he came in.
"When we were first introduced to him at the game at Carlisle he said to us that from what he'd seen of our last three games, he felt we had the quality to survive in this division and from that Monday the intensity went up massively compared to what we were used to."