The 24-year-old, son of former Glovers boss Gary, was out of contract in the summer and moves north for a nominal fee.
And he said the chance to work with controversial head coach Graham Rix swung his decision.
He told the Hearts website: "It all happened quite quickly. My contract was up at the end of the season and there had been rumours that Hearts were watching me along with a few other clubs from England.
"Once I knew Graham Rix was interested, that was it for me. There was only one place I wanted to come.
"Among players all over England he has an absolutely fabulous reputation as a coach and a manager.
"His whole ethos on the game of football - from the way he coaches, the way he wants his teams to play, and the ideas he puts across to his players - has seen him forge a great reputation among players in England."