Thorpe, who stands at 6' 1'' and can play in either defence or midfield, penned a loan deal with the Bantams this Monday that will keep him at the Coral Windows Stadium until the end of the regular season.
Subject to receiving the relevant clearances, Thorpe could now be included in Bantams boss Phil Parkinson's plans for this Saturday's Easter home fixture with fellow Play-Off contenders Millwall.
Thorpe will wear shirt number 21 during his time at Valley Parade this season.
Speaking about the move to the Bantams, Thorpe said: "The club obviously has a lot to play for at this stage of the season and I want to help where I can.
"I can play in a couple of areas and I am happy to slot in different positions to help out the team.
"Every game between now and the end of the season is going to be difficult - nearly every team has a lot to play for - so I'm ready to give it my all."
Parkinson added: "I felt we needed extra cover in defence and midfield, and Tom can play in both positions.
"He is a young player with a lot of promise and we look forward to working with him."
The 23 year-old has featured seven times for Rotherham's first team this campaign, scoring twice, after joining the Millers on a free transfer from Manchester United last summer.
During his time at Old Trafford, Thorpe skippered a United side that included Jesse Lingard, Paul Pogba and Ravel Morrison to FA Youth Cup success in 2011.
After beating the likes of Liverpool, West Ham United, Newcastle United and Chelsea in the earlier rounds, the Red Devils secured the cup by defeating Sheffield United 6-3 on aggregate in a two-legged final.
He was also captain for United when they secured the inaugural Under-21 Premier League title at the end of the 2012/2013 season. Along with those honours, Thorpe won the Lancashire Senior Cup and the Manchester Senior Cup with the Premier League giants.
Thorpe was first involved in United's senior team when he was listed as an unused substitute for their League Cup third round tie at Leeds United in September 2011.
Three years later, Thorpe actually made his first team debut for Man Utd when he came on as a late sub in their home Premier League match with West Ham United.
While at Old Trafford, Thorpe enjoyed two loan spells in the Championship with Birmingham City during the 2013-2014 season.
The Manchester-born player has represented England at Under 16, Under 17, Under 18, Under 19, Under 20 and Under 21 level.
He was part of the England squad that won the 2010 UEFA European Under-17 Championships. Thorpe was named as England Under-19 captain in the 2012 UEFA European Under-19 Championships.
He was also included in the England squad for the 2013 FIFA Under-20 World Cup.