Fans were quick to congratulate Osher and Audrey on their anniversary, including several former Bachelor contestants.
"Happy anniversary guys," wrote season five winner Laura Byrne.
"Awww happy anniversary you two," season six contestant Brittany Hockley penned.
One follower also remarked: "I love to hear people talk about such love and respect for their partners you beautiful people."
The couple met in 2014 during filming for season two of The Bachelor - whilst Osher is obviously the show's host, Audrey was working as a makeup artist.
"The day she started I turned up on the show and there was this beautiful vision of light," Osher recalled to the Sydney Morning Herald.
Osher and Audrey tied the knot in December 2016 in NSW's Hunter Valley in front of 200 guests, including Bachelor couples Tim Robards and Anna Heinrich, and Sam Wood and Snezana Markoski.
"I think it's amazing that we are the only successful couple from the Blake [Garvey] season," Audrey remarked.
Osher is stepdad to Audrey's daughter Georgia from a previous relationship and the couple welcomed son Wolfie in August 2019.
"The only idea for 2020 would be that the most important job I have, which is being a husband and father, is the one I do best," he told the publication.
"All I want to do is build a future for these kids, that's it. And for someone as selfish as me that's a big deal."