The St Johnstone boss pipped Steven Gerrard to the award in the month that Rangers clinched the title for the first time in 10 years.
Davidson led the Perth side on an impressive charge to secure a top six position after winning the Betfred Cup at the end of February.
Saints enjoyed league victories over Hibs and Ross County, and an away draw with Hamilton earlier in the month.
Davidson said: “I’m absolutely delighted to win the SPFL Premiership Manager of the Month award. I’m very proud.
“Credit to my backroom staff and the players for their efforts all season, but we have been particularly strong since the turn of the year. I appreciate all their efforts and the efforts of everyone at the club.
“Our aim now is to push on and have a strong finish to the domestic season as we still have plenty to play for.”