Leinster After leaving school in 2016, Doris spent a year in the
Leinster sub-academy before entering the academy in summer 2017. After a series of strong performances captaining the
Ireland Under-20s, Doris was promoted two years early to Leinster's senior squad ahead of the 2018–19 season, after just one year in the academy, and having made his senior debut the previous season. On 18 December 2023, the
IRFU announced that Doris had been given a three-year 'central contract' paid by the union, extending his time at Leinster until July 2027. In April 2025, he was nominated for Champions Cup Player of the Year 2025.
Ireland Youth Doris played for
Ireland Under-20s in both 2017 and 2018, captaining them in the
2018 World Rugby Under 20 Championship. Despite a poor campaign from Ireland, he was one of the standout players of the tournament. He has 14 Ireland under-20 caps despite being injured for the entire
2018 Six Nations Under 20 Championship.
Senior Doris received his first call up to the senior
Ireland squad for the
2020 Six Nations Championship, and made his debut when he started at
number 8 in Ireland's opening fixture against
Scotland on 1 February 2020, though a concussion meant that his debut lasted only four minutes. Doris missed the
2021 Six Nations and returned to play for Ireland in the summer and autumn internationals playing a starring role in Ireland wins against
Japan, New Zealand and Argentina. Doris also scored his first tries for Ireland in the matches against New Zealand and Argentina. Doris was selected by his fellow players as the Irish men's Players’ Player of the Year 2023 at the Rugby Players Ireland awards. On 11 February 2024, Doris captained the Ireland team for the first time in their game against
Italy in the
Six Nations Championship. In October 2024, he was named as squad captain ahead of the
2024 Autumn Nations Series. In November 2024, he was nominated for
World Rugby Player of the Year award for 2024 and named at No.8 in the
2024 World Rugby Dream Team of the Year. He was named captain of the
Irish squad ahead of the
2026 Six Nations. == Career statistics ==