Brooke Diamond O’Brien is in her 15th season as the head women’s lacrosse coach at Washington and Lee. In 2020, she was named the department's Senior Woman Administrator. 

Over her 14 seasons, O'Brien has led the Generals to a 202-57 (.780) overall record. The Blue and White has won 12 ODAC titles (111-4, .965 winning percentage in league play) and made 12 trips to the NCAA Tournament, highlighted by a Final Four appearance in 2017. She has been named the ODAC Coach of the Year eight times, the VaSID Coach of the Year three times and was the IWLCA Chesapeake Region Coach of the Year in 2017 and 2019. 

The W&L women's lacrosse players have thrived under O'Brien's leadership. A total of 19 players have combined for 23 IWLCA All-America accolades, including five first team honorees. O'Brien's players have also totaled 51 IWLCA all-region laurels, 39 VaSID All-State citations and 90 All-ODAC honors. She has coached six ODAC Player of the Years, three ODAC Offensive Player of the Years, two ODAC Defensive Player of the Year, two VaSID Player of the Years, one VaSID Offensive Player of the Year, one VaSID Defensive Player of the Year, four ODAC Rookie of the Years and five ODAC/Farm Bureau Scholar-Athlete of the Years. 

The most successful season in program history came under O'Brien's watch in 2017. The Generals went 19-2 overall (setting the W&L single-season record for victories) and captured the program’s eighth-straight ODAC Title. The Blue and White advanced to the NCAA Semifinals for the first time in program history, before falling to TCNJ, 5-4, in double overtime. W&L earned its first No. 1 ranking in the Nike/US Lacrosse that year, and for her efforts, O’Brien was named the IWLCA Chesapeake Region, ODAC and VaSID Coach of the Year. 

During the 2021 season, W&L notched a 14-1 record, advancing to the NCAA Tournament Regional Semifinals. During the season, the Generals extended the program-record home win streak to 30 contests and broke the overall win streak with 18 straight victories. During the campaign, the team also broke the single-game record for goals (30) and margin of victory (29). O'Brien earned her 200th career victory in the semifinals of the ODAC Tournament. 

In 2019, the team totaled the second-most wins in program history, finishing the year 18-3. W&L defeated four Top 20 teams during the season, advancing to the NCAA Tournament Regional Semifinals. The Blue and White led Division III with the fewest turnovers per game (11.86), and also set a new program single-season scoring record with 351 goals. The Generals claimed their 10th straight ODAC Championship, and notched 15 straight victories during the season, while going a perfect 11-0 at home. W&L also swept all five major ODAC honors, while putting nine players on All-ODAC teams. O'Brien was named the IWLCA Chesapeake Region Coach of the Year at the conclusion of the season. 

The Generals continued their ODAC streak under O'Brien in 2018 and claimed their ninth straight league championship, while making the NCAA Tournament for the ninth consecutive year. W&L finished 16-5 overall and went a perfect 8-0 in the ODAC. The Blue and White fell in the second round of the NCAA Tournament at York (Pa.). O'Brien claimed the 150th victory of her career during the season.

O'Brien's first campaign at W&L resulted in one of the best seasons in program history. The Generals set a then school record for wins in a season (17-3) and at the time, achieved the highest national ranking (5th) in the history of the program. W&L went undefeated in conference play, claimed the conference tournament title and advanced to the second round of the NCAA Tournament.

In 2014, O'Brien led the team to another 17-3 mark. The Generals claimed the ODAC title and advanced to the NCAA Tournament regional round after taking down Denison, 13-5, in the second round at home. W&L's season came to an end when it fell to fourth-ranked TCNJ in the regional round. Coach O'Brien also recorded her 100th career win in the ODAC title game after going a perfect 10-0 in conference play and 11-0 at home.

In the 2015 campaign, the Blue and White claimed a 16-3 overall record and a 10-0 mark in ODAC action. After claiming an ODAC title, W&L appeared in the NCAA Tournament and defeated Sewanee, 18-4, in the second round. The Generals’ advanced to the regional round of the playoff, before falling to 17th-ranked Fredonia.

O'Brien came to W&L after serving as an assistant women's lacrosse coach at Amherst College and as a graduate assistant women's soccer coach at Smith College from 2005-07.

At Amherst, O'Brien assisted in all aspects of the program and helped lead the Lord Jeffs to a No. 6 ranking and the NCAA Quarterfinals in 2006. At Smith, O'Brien was also involved in all aspects of the women's soccer program and helped lead the team to a 14-7-1 record and an ECAC New England Championship during the 2006 season.

O'Brien graduated Magna Cum Laude from Amherst in 2003 with a bachelor of arts in psychology and law, jurisprudence and social thought. She earned a total of 12 letters as a member of the women's lacrosse, women's soccer and women's basketball teams and served as a captain for all three sports.

In lacrosse, she was a two-time First Team All-America selection and two-time Kelly Award winner as the Division III National Goaltender of the Year. She was named the Intercollegiate Women's Lacrosse Coaches Association (IWLCA) Division III Scholar-Athlete of the Year and was selected the Division III Women's Lacrosse Tournament's Most Outstanding Player in leading the Lord Jeffs to the 2003 National Championship.

In soccer, O'Brien was a four-time all-region selection as a goalkeeper, leading Amherst to the 2001 NESCAC Championship and an NCAA Tournament Runner-Up finish. She was a two-year captain of the basketball team. Following her playing career, O'Brien was presented the Howard Hill Mossman Trophy as the senior athlete who brought the greatest honor to athletics at Amherst College during their four years.

A native of Longmeadow, Mass., and an alumnus of the Loomis Chaffee School in Windsor, Conn., O'Brien worked as a financial analyst with Goldman, Sachs & Co., in New York and London from 2003-05. She earned a master of science in exercise and sports studies from Smith College in the spring of 2007.

O'BRIEN YEAR-BY-YEAR AT W&L