O'Riordan returns to Sydney eight months after hanging up the boots, having called time on his career last August following 34 games in the red and white across five seasons.
The Irishman has now ventured back to the Harbour City club to aid the Swans' coaching ranks, with AFLW senior coach Scott Gowans currently away from his duties as he undergoes surgery for prostate cancer.
O'Riordan expressed his delight in taking on an assisting role at his old club, looking to help mentor and develop Sydney's emerging ranks.
"If I can pass on one message to the girls, it's to drive your own career and you can steer it in any way you want to," O'Riordan said in a club announcement.
"If you put the hard work in and put your head down, you will reach whatever goal you want to reach.
"It's very exciting to be back and be involved (again) with the Swans. I make no secret of what the place means to me (and will be) helping the girls out as much as I can.
"It's nice to be able to come in and help out, and hopefully pass on some knowledge I have from the game."
The announcement sees O'Riordan, who ventured to the Swans in 2015 from Tipperary, dip his toe into the coaching world for the first time in his career, with the pacey defender set to look toward his ex-mentor in John Longmire for guidance.
"'Horse' has been an incredible coach for me and my only coach since I've been in Australia, so I might even lean in and get some advice from him from time to time," O'Riordan said.
Sydney's AFLW side were unable to secure the first win in their history during Season Seven - the club's inaugural season in the competition.
Dates and fixtures for the upcoming AFLW campaign are yet to be confirmed by the AFL.