The 2017 Six Nations Under 20s Championship, was the 10th series of the Six Nations Under 20s Championship, the annual northern hemisphere rugby union championship. Wales were the defending champions. The competition was won by England, who completed a Grand Slam by winning all their five matches.

For the first time, the 2017 tournament used the bonus point system common to most other professional rugby union tournaments. As well as the standard four points for a win and two for a draw, a team scoring four tries in a match received an additional league table point, as did a team losing by seven or fewer points. Additionally, to ensure that a team winning all of its five matches (a Grand Slam) would also win the Championship, three bonus points were awarded for this achievement.

* England were awarded an extra 3 table points for achieving the Grand Slam.

Some of the matches are broadcast on television by France 4 and Sky Sports.