Franklin, 33, joined the side during their Christmas break, having come off a successful Bunnings NPC campaign with national champion Taranaki last year.
His signing boosts an area of concern for the Force, their locking strength. He played 85 times for the Highlanders, made nine appearances for the Māori between 2014 and 19, and has also played in Japan for Kobelco Steelers.
Force coach Simon Cron said Franklin would immediately improve the quality and experience of locking for the side.
"An area that we're light on has been lock, so we've been looking for somebody who can add value to the team straight away.
"Tom has knowledge around lineouts and skills around the park, and most recently, he was in the winning-Taranaki team at the NPC level. Talking to his forwards coach, he was a big part of that.
"I coached against Tom when he was at the Highlanders, and he was one of the best defensive lineout readers that we'd coach again. I was lucky to chat with him in Japan when he played for Kobe, and you could see what he added.
"With the age of our tight-five forwards, we needed somebody a bit more experienced. Tom brings a high-skill, high-paced game with a good rugby brain and good knowledge.
"He's also an awesome person who'll help bring through a lot of our guys and play at the highest level still."
Franklin said he was happy with the chance to play in Perth.
"I had a good chat to Crono and the coaches which excited me about the move, and I heard good things from ex-players like Marcel Brache who spoke about how the club is growing.
"I'm excited about the opportunity to be part of something with high aspirations to go to the next level, and excited to be back in Super Rugby Pacific and take on the challenge."
