Career Accolades
- NCAA champion (2017)
- Three-time Pac-12 champion (2017-18, 2020)
- Two-time Pac-12 Academic Honor Roll (2019-20)
- Pac-12 All-Academic Honorable Mention (2018)
As a Senior (2020-21) • Pac-12 Champions
- Pac-12 Academic Honor Roll
- Appeared in 13 matches, making 12 starts
- Scored a goal in Stanford's 4-0 win over UCLA (3/6)
- Dished one assist in a season-opening win over Pacific (2/12)
- Totaled 10 shots, including five on goal
- Played a season-high 71 minutes in a win over No. 6 Washington (4/17)
- Played at least 45 minutes in 10 games
- Part of a Stanford offense that ranked top-10 nationally in total goals (30), total assists (32) and total points (92)
As a Junior (2019)
- Pac-12 Academic Honor Roll
- Appeared in nine matches
- Totaled four shots, one on goal
- Played a season-high 36 minutes in the first match of the year at Penn State (8/30)
As a Sophomore (2018) • Pac-12 Champions
- Pac-12 All-Academic Honorable Mention
- Played in 18 matches, started one and had one goal and one assist
- First career goal came in a 3-0 home victory over UCLA (9/30)
- Also assisted on Arda Bulut's 107th-minute winner at Washington (10/14)
- Put all four of his shots on frame
As a Freshman (2017) • NCAA Champions • Pac-12 Champions
- Appeared in 16 matches, made one start and played 314 minutes
- Started in his collegiate debut, a 1-0 home victory over San Francisco (9/15)
- Totaled three assists in wins over the Dons (9/15) and San Diego State (9/28) and in a 1-1 draw with No. 19 Washington (10/12)
Prior to Stanford
- A 2017 graduate of Broomfield High School in Broomfield, Colo.
- Member of Colorado Rush Academy from 2013-17
- U.S. Soccer Development Academy playoffs in 2014 and 2015
- Scored a team-leading 16 goals for the U-18's in 2016-17
- Started 20 of 26 games for the U-18's in 2015-16 and led the team with 10 goals
- USSDA Player of the Week in June 2014
- Scored his first USSDA goal in a summer showcase as an incoming high school freshman
- Generation adidas Real Madrid Select Team (Aug. 2015)
Personal
- Full name is Jack Tiernan O'Brien
- Born in Louisville, Colo.
- Son of Kelly and Don O'Brien
- Has two brothers, Thomas and Sean
- Brother, Thomas, played soccer his freshman season at Davidson in 2013 before transferring to Gonzaga
- Great-grandfather Peter Kmetovic was a prominent member of the Wow Boys, Stanford's 1940 national championship football team
- 1941 Rose Bowl Player of the Game
- Third overall pick in the 1942 NFL Draft
- Grandfather, Tom Kmetovic, was a defensive back at Colorado
- Maintained a 4.4 GPA in high school
- Volunteered with Broomfield FISH Food Bank, A Previous Child and Circle of Friends