It's not the first time the singer has referred to his partner as his wife, though they have not publicly confirmed their marriage.
Just last month, People reported that the Canadian singer was apparently not over his ex, Selena Gomez whom he dated on and off for years.
"My wife is awesome", the singer captioned the photo, showing Hailey wearing baggy I AM GIA trousers, a white cropped t-shirt and a red baseball cap.
Meanwhile, Justin Bieber is reportedly scaling back on work even than Hailey Baldwin. The news comes weeks after she filed to trademark her married name.
Image copyright Getty Images Image caption Justin stops at the Buckingham Palace fountain to sing songs for Hailey on a trip to London in September. "They have had a few conflicts about it", an insider added.
"She encourages him to do whatever he wants to do, and is encouraging him in this season of self-discovery".
In other news, there was a report that claimed the marriage of Justin Bieber and Hailey Baldwin are at the rocks.
Gossip Cop assured that Justin Bieber and Hailey Baldwin are not headed for a divorce.