| Seán O'Brien | |
| Birth Name: | Sean Finn O'Brien |
| Birth Date: | 2000 7, df=yes |
| Birth Place: | Pittsburgh, Pennsylvania, United States |
| Weight: | 106kg (234lb) |
| Ru Position: | Flanker |
| Years1: | 2023- |
| Clubs1: | Connacht |
| Apps1: | 5 |
| Points1: | 5 |
| Years2: | 2020-2023 |
| Clubs2: | Leinster |
| Apps2: | 3 |
| Points2: | 0 |
| Ru Clubupdate: | 29 Jan 2023 |
| Repyears1: | 2020 |
| Repteam1: | Ireland U20s |
| Repcaps1: | 3 |
| Reppoints1: | 0 |
| Ru Ntupdate: | 29 Jan 2023 |
| School: | Blackrock College |
| University: | UCD |
| Ru Currentteam: | Connacht Rugby |
| Clubs3: | LA Giltinis - on loan |
| Apps3: | 6 |
| Years3: | 2020 |
Seán O'Brien (born 31 July 2000) is an American born Irish rugby union player, currently playing for Pro14 and European Rugby Champions Cup side Connacht. His preferred position is flanker.[1] and Number 8.
Although born in Pittsburgh, Sean returned to Dublin before the age of 1, and played his junior rugby at Greystones Rugby Club in Wicklow before winning a JCT and SCT medal with Blackrock College.
Sean was part of the Leinster academy from 2020 to 2023 when he was then offered a professional contract with Connacht Rugby.[2]
O'Brien was named in the Leinster Rugby academy for the 2020–21 season.[3] He made his debut in Round 15 of the 2020–21 Pro14 against .[4] [5]
O'Brien was named in the Connacht Squad for the 2023–24 season. He made his debut, and received his first cap vs Ospreys.[6] O'Brien then travelled with the squad to South Africa, playing in both away games, vs the Sharks and Bulls, scoring his first URC try in Durban.[7]