[3] The Championship was won by Ireland on 10 March 2018, with their four wins (three with try bonus points) from the first four matches sufficient to place them out of reach of the other participants ahead of the final round.

After a 24–15 victory against England on the final day, Ireland secured a Grand Slam, their third ever, alongside a Triple Crown.

[6][7][8] 1 Dylan Hartley was ruled out of round 4 due to injury, and Owen Farrell captained England in his absence.

[9] 2 Guilhem Guirado was ruled out of round 5 due to injury, and Mathieu Bastareaud captained France in his absence.

[10] 3 Alun Wyn Jones was dropped from the match-day team to play Italy in round 4, and Taulupe Faletau captained Wales in his absence.