The 23-year-old, who has been on trial at the Scottish Championship side since his contract expired at the end of last season, has signed a two-year deal with the option of a third.
He scored the third goal in the Bantams’ historic 4-2 victory over Chelsea at Stamford Bridge in the fourth round of last season’s FA Cup, a game that has gone down as one of the biggest shocks in the history of the competition.
“I lived on Copland Road when I was young, so Ibrox was near-enough in my back garden,” Halliday told RangersTV.
“My whole family are mad Rangers fans, and I had a season ticket since I was four years old and had it for 15 or 16 years and followed the team everywhere.
“It feels as if a fan has got the chance to play for Rangers, and it has always been my dream, so it will maybe not sink in until I walk out in front of 50,000 fans at Ibrox.”
Halliday was a member of the Rangers Academy until he was 15 years old before being released and moving to Livingston, where he started his senior career and scored 15 goals in more than 30 appearances.
Gordon Strachan signed him for Middlesbrough in 2010, where he made 44 first team appearances. Loan spells followed at several English clubs, including Blackpool and Walsall, before he signed permanently for League One side Bradford in October last season.
Halliday admitted his release from Rangers as a youngster hit him hard.
“I stopped playing altogether for around three months when I left Rangers where I just didn’t touch a ball,” he said, crediting Livingston coach Scott Allison for reviving his teenage career.
“Eventually, I just wanted to go to the park with my pals and have a kick about, before Scott convinced me to come out of early retirement to take me to Livingston.
“That turned out to be a good decision to do that as I managed to get to play first-team football at an early age.
“At the time, being released from Rangers was the worst thing that happened in my career, but looking back, it’s probably the best thing to ever happen in my career.
“I managed to get away and get football at a young age, and I always knew deep down that there would be a chance that I could come back here, and I’m just happy it’s happened now.
“It was always something I wanted to have on my CV – that I’d played for Rangers and thankfully the opportunity has come a lot earlier in my career.
“If the club is doing well and I am doing well, then it is a club I can see myself being at for a long time.
“Hopefully it all goes well on the park but we have started to get the foundations to get this club back where it belongs and I am pretty sure it is going to happen in no time.”