Harris attended college at the United States Naval Academy, majoring in general engineering, and playing college baseball as a pitcher and infielder for the Midshipmen.
 Having ended up at the Academy by chance, a Navy football recruiter named Buddy Green watched him pitch a bullpen session in high school.
 Green found out that Harris was not interested in football, but was open to attending the Naval Academy, so he made phone calls on his behalf.
 In spite of the path that led to his entrance into Navy, Harris spent his freshman year as a corner infielder and utility player.

However, when incoming coach Paul Kostacopoulos watched Harris throw during a practice session after his freshman season, he asked him to pitch in the bullpen, where he reached 91 miles per hour (146 km/h).
 Impressed with the tryout, Kostacopoulos expanded Harris' role to pitching.
 As a sophomore, he claimed the Patriot League pitching triple crown with a 10–3 record, 1.74 earned run average (ERA) and 113 strikeouts (SO) in 13 games started.
 He also hit one home run with 27 runs batted in (RBI) and a .333 batting average.

The next season, as a junior, Harris went 8–5 with a 2.14 ERA and a Patriot League-record 119 strikeouts.
 He also emerged as a force on offense, with a league-leading eight home runs, 47 RBI and a .293 average.
 He also led Navy in runs batted in, doubles (10), triples (four) and slugging percentage (.534).
Baseball America named Harris a third-team All-American.
 One of his teammates at Navy, Oliver Drake, also a pitcher, was a selection in the same amateur draft, and made his major league debut for the Baltimore Orioles the month following Harris.
 Harris' college pitching career totals included a record of 20–13 with a 2.51 ERA and 291 strikeouts over ​222 ¹⁄₃ innings.
 At the plate, he batted .295 with 105 runs scored, 16 home runs and 112 RBI.

In 2007, he played collegiate summer baseball in the Cape Cod Baseball League for the Bourne Braves.
When he graduated, he was one of the highest-rated pitching prospects for the amateur draft, with a fastball that could reach 95 miles per hour (153 km/h) and a cutter with the ability to break bats.
Harris attended college at the United States Naval Academy, majoring in general engineering, and playing college baseball as a pitcher and infielder for the Midshipmen.  Having ended up at the Academy by chance, a Navy football recruiter named Buddy Green watched him pitch a bullpen session in high school.  Green found out that Harris was not interested in football, but was open to attending the Naval Academy, so he made phone calls on his behalf.  In spite of the path that led to his entrance into Navy, Harris spent his freshman year as a corner infielder and utility player.
However, when incoming coach Paul Kostacopoulos watched Harris throw during a practice session after his freshman season, he asked him to pitch in the bullpen, where he reached 91 miles per hour (146 km/h).  Impressed with the tryout, Kostacopoulos expanded Harris' role to pitching.  As a sophomore, he claimed the Patriot League pitching triple crown with a 10–3 record, 1.74 earned run average (ERA) and 113 strikeouts (SO) in 13 games started.  He also hit one home run with 27 runs batted in (RBI) and a .333 batting average.
The next season, as a junior, Harris went 8–5 with a 2.14 ERA and a Patriot League-record 119 strikeouts.  He also emerged as a force on offense, with a league-leading eight home runs, 47 RBI and a .293 average.  He also led Navy in runs batted in, doubles (10), triples (four) and slugging percentage (.534). Baseball America named Harris a third-team All-American.  One of his teammates at Navy, Oliver Drake, also a pitcher, was a selection in the same amateur draft, and made his major league debut for the Baltimore Orioles the month following Harris.  Harris' college pitching career totals included a record of 20–13 with a 2.51 ERA and 291 strikeouts over ​222 ¹⁄₃ innings.  At the plate, he batted .295 with 105 runs scored, 16 home runs and 112 RBI.
In 2007, he played collegiate summer baseball in the Cape Cod Baseball League for the Bourne Braves. When he graduated, he was one of the highest-rated pitching prospects for the amateur draft, with a fastball that could reach 95 miles per hour (153 km/h) and a cutter with the ability to break bats.
Mitch Harris (baseball)