The 2020 Six Nations Under 20s Championship was the 13th series of the Six Nations Under 20s Championship, the annual northern hemisphere rugby union championship.

Ireland were the defending champions, having won the 2019 Championship with a Grand Slam.

[1] The tournament was suspended with three games left to play due to the COVID-19 pandemic[2] and cancelled in August with no winner announced.

At the point of cancellation, Ireland had beaten the three other Home nations, and as such had won a triple crown, which is officially recognised despite the cancellation of the tournament.

[3] Table ranking rules