The 28-year-old joins after four seasons at Oakwell, where he made over 180 appearances, scoring 43 goals and providing 27 assists.
He previously joined Barnsley from Burnley in 2022 and enjoyed a prolific campaign last season with 11 goals and five assists.
Across his career he has surpassed 100 goal contributions in 297 appearances, with most coming in League One. He becomes Graham Alexander’s second summer signing for the Bantams.
“I am absolutely delighted to sign for Bradford City. You look at the last two seasons, the club is only going one way and I am ready to get on board with where the club wants to go,” said Phillips
“For me personally, I had a really good chat with the manager and met him a couple of weeks ago. The way he spoke about the club and his idea on how he wants to play really suits me as a player and I think we will work really well together.
“I have played a lot of games in League One and know what the division is about. I am hoping to bring my experience to the squad.”