The England Knights international, who moves from Salford Red Devils on a one-year deal, has plenty of Super League pedigree having played more than 100 games for Warrington with whom he scored a Grand Final try in 2016.
Patton also helped Wolves win the Challenge Cup at Wembley just two years ago.
However, with the likes of Great Britain stars Blake Austin and Gareth Widdop ahead of him, he left them for Salford this term but struggled to make his mark.
Patton said: “I am excited to be joining Bradford. It has been a weird couple of seasons for me not playing much and after meeting John Kear and Mark Dunning and seeing the club I am excited to get my career back on track and enjoy my rugby again.
“I’ve seen a lot of the Championship games and the standard is definitely getting better.
“It is a good competition and hopefully I can make a difference.
“From talking to John, he thinks we aren’t far away and can push for the top-two next year and closer for promotion. Hopefully I can help with that.”
Bradford’s hopes of promotion were ended with Saturday’s play-off defeat at Batley Bulldogs but, having already added former Leeds Rhinos forward Jordan Baldwinson for 2022, they are intent on improving next term.
Kear said: “Dec broke onto the scene at Wolves and only a log jam of quality half-backs prevented him getting a regular place. But I have always admired his talent. To get a Super League standard half-back is a real big coup for the club and is a massive statement of intent.
“Dec wants to play Super League, we want to get back into Super League and he will certainly be a key contributor towards that goal.”
Meanwhile, Bulls have been sanctioned by the RFL after a section of fans directed homophobic abuse towards referee James Child – who spoke publicly on the eve of the season about his sexuality – during their game against Newcastle Thunder in June.
The RFL launched an investigation and a Bulls statement read: “The investigation was satisfied that Bradford were unaware of the comments and the club have accepted that match stewards should have heard the remarks and intervened.
“In reaching an ‘Agreed Decision’ with the RFL, the club accepts that the language which was heard at the fixture in question was offensive and homophobic and has no place in the sport of rugby league.
“The club have committed to spending a minimum of £3,000 to promote an Inclusivity and Diversity Celebration home fixture in 2022, in lieu of a fine, as a more progressive and positive intervention – with an additional £1,000 fine suspended until the end of the 2022 season.”
Elsewhere, ex-Hull KR, Huddersfield Giants and Castleford Tigers scrum-half Jamie Ellis, 31, has also dropped down to the Championship after leaving Leigh Centurions for part-time York City Knights on a one-year deal.
However, he will not be getting a job and intends to be “like a full-time player in a part-time environment” to rediscover his best form.