John Thomas McNamara, a father-of-three, was a leading amateur rider before being seriously injured.
He fractured two vertebrae in his neck after being thrown from his horse Galaxy Rock in the Fulke Walwyn Kim Muir Challenge Cup on 14 March, 2013.
He moved back home to Limerick in 2014 after being discharged from the North West Regional Spinal Injuries Centre.
I've done nothing but cry all morning
Adrian McGoldrick, senior medical officer for the Irish Turf Club confirmed McNamara "passed away peacefully during the night".
McNamara rode four winners at the Cheltenham Festival, including guiding Teaforthree to victory in the 2012 National Hunt Chase.
He won the same race in 2002 on Rith Dubh, was successful in the Cross-Country Chase with Spot Thedifference three years later and won the 2007 Fox Hunter Chase on Drombeag.
A minute's silence will be held at the Galway Festival on Tuesday as a mark of respect, before the second race at 17:45 BST.
Sir AP McCoy, 20-time champion jump jockey, on BBC Radio 5 live:
I would hate for him to be looking down on me at this moment in time because I've done nothing but cry all morning.
He was every bit as experienced as me and talented as I am and he had a fall.
I'll never forget that day for the rest of my life. The doctor Adrian McGoldrick pulled me to one side because I'm president of the Injured Jockeys Fund in England and said to me 'he's not very good, he's been resuscitated and it's touch and go whether he's going to make it or not'. It's a memory that will stick with me forever.
He was a very tough man. Very mentally tough and has been for the last three and a half years since the accident. He was a brilliant man and a brilliant amateur jockey. The last three and a half years have been tough for him and his family - his wife was unbelievable for him. It is a sad day.
He made the best of it and tried to make it easy for others around him.
I know he would like us to remember to good days. I'd like him to be remembered as a fantastic person, fantastic jockey and a fantastic human being.
BBC Sport's Frank Keogh:
JT McNamara will be remembered for his distinguished, stylish career in the saddle and his formidable strength of character after serious injury.
The jockey had told friends he intended to retire in the summer of 2013 but a fateful fall that March prematurely ended his career.
Weighing room colleagues were in shock and the Cheltenham Gold Cup the following day was run against a sombre backdrop.
A plaque above where he sat at Cheltenham celebrates his 16 winners at the track, including four at the Festival.
When Bruce Springsteen played in Limerick, he dedicated his song My Hometown to the stricken jockey. He was a much-loved and respected figure.
Irish jockey JT McNamara, who was paralysed after a fall at the 2013 Cheltenham Festival, has died aged 41.