Kinghorn, who can also play on the wing, has an impressive strike rate for club and country with 23 tries in 94 appearances for Edinburgh and eight tries in 25 games for Scotland.
He said: “I’m Edinburgh born and bred and I grew up supporting the club. The club really means a lot to me. It has a very special place in my heart.
“I was 18 when I first signed so re-signing as I turn 24 is a bit mad. It’s been a whirlwind of a journey."
Kinghorn was part of the Edinburgh side which topped their conference in the Guinness Pro14 standings last season before losing to Ulster in the play-off semi-finals. The capital club have struggled to reproduce that form so far this season but the full-back is confident the future is bright for Edinburgh who will soon move into a new stadium on the back pitches of Murrayfield.
Head coach Richard Cockerill has signed two new players from Harlequins for next season, with the Scotland centre James Lang and second-row forward Glen Young agreeing to move north.
“I’ve always played here and love representing the city,” Kinghorn added. “The pinnacle of that will be when we get into our new stadium and the fans are allowed back in. I think that day will really show how much the club means to the fans, how much the players care about representing them, and how much they mean to us. It’s really something to look forward to.
“My goals personally are to keep developing to the best of my ability, keep getting better every day and every week, and keep striving for success with the club.
“It’s a challenging environment and there’ll always be change, but we’ve managed to sign and re-sign some really great players, which is great news for Edinburgh.
“I think the future is really bright. I think the squad we’ve developed – and continue to develop – is really exciting.
“I feel like we’re capable of pushing on for greater things and I want to be a part of that."
Cockerill added: “We’ve enjoyed bringing supporters some good news these past couple of weeks as our plans for the future continue to take shape.
“Blair is a local lad come good, which is always nice to see. He’s also a gifted athlete who’s developed into fine rugby player over the past few seasons with us, and continues to get better.
“He’s racked up an impressive number of appearances and tries for club and country for someone so young and is a real asset to us in the back-field, particularly in a counter-attacking sense.
“He’s regular starter for us and sets a good example for those coming through on what it takes to achieve that. It’s fantastic he’s staying with us.”