How many times have Ireland won the 6 Nations?
The 6 Nations began in 2000, when Italy joined the 5 Nations
championship. Since the 6 Nations came into existence and up to the
end of the 2018 championship, Ireland has won it four times, in
2009, 2014, 2015 and 2018.
Going back to the 5 Nations and its various predecessors and
including the 6 Nations, Ireland has won 14 championships, 8 of
which they were joint winners.