Ronaldo was in impressive form throughout the month of April, scoring five times in just four matches for the Red Devils.
The latest award now moves the Portuguese international to within one of the Premier League record of seven, which is held by Tottenham striker Harry Kane, and former Manchester City star Sergio Aguero.
In the month of April, Ronaldo scored his 100th Premier League goal, in a 3-1 defeat at Arsenal, while he also registered his 50th club hat-trick in a 3-2 win over Norwich City
Ronaldo notched his fifth goal of the month, equalising to earn a 1-1 draw with Chelsea.
The forward topped an eight-man shortlist that also featured Nathan Collins, Kevin De Bruyne, Bruno Guimaraes, Gabriel Jesus, Son Heung-min, Thiago and Leandro Trossard.
The honour is, however, even more impressive as he missed United’s heavy 4-0 defeat to Liverpool in that month due to being on special leave.
Ronaldo missed the match at Anfield due to grieving over the tragic death of his newborn baby son.