The 29-year-old from New Zealand, who can play at both fly-half and centre, joins from Auckland-based Super Rugby franchise the Blues.
A former New Zealand U19 and U21 player, Bowden has previous Aviva Premiership experience, having represented London Irish and Leicester Tigers before returning to New Zealand in 2014.
“I know what a tough, entertaining competition the Aviva Premiership is, so I can’t wait to get back to England and get started with Bath," said Bowden. "There will be some familiar faces there as well, which is always good - guys like George Ford, who I played with at Tigers, and Toby Booth and Neal Hatley, who I worked with at Irish."
Head Coach Mike Ford commented: "Dan's versatility, goal kicking and experiences both in Super Rugby and the Aviva Premiership make him a very good fit for us. I've seen him play many times before and know his personality, so I'm confident he'll be a big hit at the Club."
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