The player, who scored his 100th career try against Bradford for Hull KR in the Qualifiers in 2015, is looking forward to helping the Bulls’ push for promotion in 2016.
“Bradford is a great club with plenty of history and they need to be back in the Super League,” Welham told his new club’s official website.
“If I can help with my experience to get Bradford back into the Super League then that’s part of the job that I’ll bring to the club.
“Ultimately, Bradford and I have both got the same goal to be back playing in the Super League and hopefully this is the year that we’re going to do.
“My contract was up at Hull KR and I was looking for a new challenge and a fresh start and Bradford were interested – I wanted to move to the club.
“I did score my 100th try of my career against Bradford. Looking back at it now it was a great achievement for me to score 100 tries but against the club that I’ve now signed for, hopefully, we can have a laugh and a joke about it.
“I’ll bring experience to the squad, which always helps if you’ve got a few young or inexperienced lads playing if we come up against Super League opposition.”