The former Blackburn player played a key role as the club secured its highest ever Clydesdale Bank Premier League finish of fourth place.
He played 45 times for the Highland outfit, scoring three goals.
And as reward for his performances, Caley Thistle have handed the 22-year-old Irishman the longest contract they have issued in a number of years.
Doran told the club's official website: "Contract talks have dragged on a bit, but I'm delighted to have committed myself to Caley Thistle.
"I'm happy to be at the club and in Inverness and getting the negotiations over gives me security and enables me to plan for the future.
"It's been on my mind these past few months so it's a relief to put pen to paper. The 2011-12 season was a nightmare for me because of the shoulder injury which restricted me to only a handful of appearances. There could hardly be a bigger contrast this past season when I played every game. I managed to add a few more goals to my account, which is what I've been working on."
The Ireland under-21 cap added: "It's been an exciting season and I think we can keep the momentum going because we've got most of the team re-signed already.
"We've lost Andrew Shinnie and Antonio Reguero, but keeping the core of the squad means we don't need to get to know each other at the start of next season so hopefully we can get going right from the start.
"I'm really looking forward to next season as we've the right platform to do well again."