Cassie Young was named co-head coach of the Saint Mary's softball program in August 2021.

A four-year starter for the Belles in center field, she became one of the first two players in program history to earn All-MIAA honors in each of her four seasons on the team. The MIAA Most Valuable Player in both 2016 and 2017, she was named First Team All-Region by the National Fastpitch Coaches Association three times during her career. She went on to be named Third Team All-American in one of the three outfield positions listed in 2018 after helping lead the Belles to their first MIAA regular season title and first NCAA Tournament appearance. She was named to the NFCA Top 50 National Player of the Year Watch list at the start of both her junior and senior seasons, and she was on the NFCA Top 25 National Player of the Year list midway through her senior campaign. She is listed among the program's all-time leaders in career batting average, single season hits, career hits, career doubles, single season and career runs batted in, and career runs scored. Her career batting average of .459 is second-all time in program history as she never posted a single-season batting average below .400 in her career.

Cassie has been part of the Saint Mary's coaching staff since the 2019 season after joining the Belles as an assistant coach.

She graduated from Saint Mary's in 2018 as a business administration major with concentrations in finance and management.