A method for producing a hydroxyl group-containing vinyl ether polymer according to the present invention includes: a step of radical polymerizing at least one vinyl ether selected from vinyl ether having a hydroxyl group represented by the following formula (2): wherein R7 represents an alkylene group which is straight-chained, branched or comprises an alicyclic structure, and p is 1, 2, or 3, in the presence of water as a polymerization solvent and an azo compound represented by the following formula (1) as a polymerization initiator: wherein R1 to R4 each independently represent a hydrogen atom or an alkyl group and R5 and R6 each independently represent an alkoxy group optionally having a substituent group or an alkyl amino group optionally having a substituent group.