He was said to have been born in 1483 near Shrewsbury, and joined the army around 1500. He did not marry until he was 80 years old. He attributed his long life to his vegetarian diet and moral temperance, although when he was around 100 years old he had an affair and an illegitimate child.
In 1635 Thomas Howard, 21st Earl of Arundel, visited Parr and brought him to London to meet Charles I. Charles asked what Parr had done that was greater than any other man, and Parr replied that he was the oldest man to have performed penance (for his affair). In London he was treated as a spectacle, but the change in food and environment apparently caused his death. Charles I arranged for him to be buried in Westminster Abbey on November 15, 1635.
William Harvey, the physician who discovered the circulation of the blood, performed an autopsy on Parr's body.
The poet John Taylor wrote about Parr in his 1635 poem The Old, Old, Very Old Man or the Age and Long Life of Thomas Parr.
It is likely that his records were confused with those of his grandfather. However, he did not claim to remember specific events from the 15th century, and he was blind and feeble when the Earl of Arundel met him, so it seems to be true that he was very old, possibly a centenarian. The whiskey brand Old Parr is named for him and recounts his claimed birth and death years on its label.