Carson Seymour Bio
Carson James Seymour (born December 16, 1998) is an American professional baseball pitcher for the San Francisco Giants of Major League Baseball (MLB). He made his MLB debut in 2025 after being selected by the New York Mets in the sixth round of the 2021 MLB Draft. Before turning professional, Seymour attended Great Oak High School and played college baseball at Dartmouth College and Kansas State University.
Standing as a right-handed pitcher developed through both Ivy League and Big 12 collegiate programs, Seymour climbed the minor league ladder across multiple organizations before reaching the majors. His journey from Temecula, California, to the Giants roster reflects steady progression through rookie, Single-A, High-A, Double-A, and Triple-A levels.
Early Life and Background
Carson James Seymour was born on December 16, 1998, in Temecula, California. He grew up in the same Southern California community that would later become home to Great Oak High School, where he developed his baseball skills. The Temecula area has produced a steady stream of amateur talent, and Seymour emerged from that pipeline as one of its notable pitching prospects.
At Great Oak High School, Seymour established himself as a draft-worthy arm, drawing attention from college recruiters across the country. His performances at the prep level set the stage for a collegiate path that took him away from home, first to the Ivy League and then to the Big 12 Conference. Those formative high school years laid the foundation for the professional career that followed.
Path to Professional Baseball
Following high school, Seymour enrolled at Dartmouth College, where he began his college baseball career in the Ivy League. The program demanded both academic discipline and athletic consistency, and Seymour developed his pitching repertoire against strong regional competition during his time in New Hampshire.
He later transferred to Kansas State University, continuing his collegiate development in the Big 12 Conference. Between his college seasons, Seymour gained valuable summer experience in two of the country’s premier wooden-bat leagues. In 2019, he played for the Harwich Mariners of the Cape Cod Baseball League, and in 2020, he joined the Rockford Rivets of the Northwoods League during a pandemic-restricted pod circuit. Those summer stints against top amateur talent helped sharpen his game before the 2021 MLB Draft.
Carson Seymour Career
Early Career (2021-2022)
The New York Mets selected Carson James Seymour in the sixth round, with the 172nd overall pick, of the 2021 Major League Baseball draft. He made his professional debut that same year with the rookie-level Florida Complex League Mets, beginning his climb through the New York farm system.
Seymour began the 2022 campaign with the Single-A St. Lucie Mets, where he posted a 4-0 record and 1.19 ERA with 27 strikeouts across seven appearances, four of which were starts. Following a promotion to the High-A Brooklyn Cyclones, he logged a 1-5 record and 3.68 ERA with 65 strikeouts over 11 games, including nine starts.
Trade and Giants Debut (2022-2023)
On August 2, 2022, the Mets traded Seymour, along with J. D. Davis, Thomas Szapucki, and Nick Zwack, to the San Francisco Giants in exchange for Darin Ruf. He started his Giants career with the High-A Eugene Emeralds before moving up the system.
In 2023, Seymour pitched for the Double-A Richmond Flying Squirrels, registering a 5-3 record and 3.99 ERA with 114 strikeouts in 112 2/3 innings pitched across 28 appearances, 23 of which were starts. That season established him as a reliable starter within the Giants organization and positioned him for a promotion to Triple-A.
San Francisco Giants Era (2024-Present)
Seymour spent the 2024 campaign with the Triple-A Sacramento River Cats, making 29 appearances, including 28 starts, and posting a 7-10 record and 4.82 ERA with 132 strikeouts across 134 1/3 innings pitched. Following the season, the Giants added Seymour to their 40-man roster to protect him from the Rule 5 draft, a sign that the organization viewed him as part of its long-term plans.
Seymour was optioned to Triple-A Sacramento to begin the 2025 season. In 15 starts for the River Cats, he compiled a 3-8 record and 3.89 ERA with 83 strikeouts over 74 innings of work. On June 27, 2025, Seymour was promoted to the major leagues for the first time, and he made his MLB debut on June 29. On September 5, 2025, Seymour recorded his first career win, allowing one run over five innings pitched against the St. Louis Cardinals. He went on to make 16 appearances, including three starts, for San Francisco during his rookie campaign, posting a 1-3 record and 4.75 ERA with 26 strikeouts over 36 innings.
Notable Events and Milestones
Seymour’s first major league win on September 5, 2025, against the St. Louis Cardinals, marked the most significant milestone of his young career. Allowing just one run over five innings in that contest provided a memorable cap to his debut season. His addition to the Giants’ 40-man roster after the 2024 campaign also represented a key organizational step, signaling that San Francisco intended to develop him as part of its pitching future.
Carson Seymour Family
Personal Life
Carson James Seymour married Sydney Campbell in 2024. The couple shares a white Labrador retriever named Goose. Seymour’s personal life has remained largely out of the public spotlight, with limited details available beyond these confirmed facts.
2025 Season Performance
Carson Seymour’s 2025 season represented his long-awaited arrival in Major League Baseball. After beginning the year in Triple-A Sacramento, where he posted a 3-8 record and 3.89 ERA across 15 starts, he earned his first big-league promotion on June 27. His MLB debut came two days later, marking the culmination of four years in the minor leagues.
During his rookie MLB campaign, Seymour made 16 appearances, including three starts, for the San Francisco Giants. He finished with a 1-3 record and 4.75 ERA, recording 26 strikeouts over 36 innings. His first career win on September 5 against the St. Louis Cardinals, in which he allowed one run across five innings, served as the highlight of his debut season.
The transition from starting in Triple-A to a mixed relief and starting role in the majors presented an adjustment period typical for first-year pitchers. The Giants’ decision to add him to the 40-man roster the previous offseason and continue developing him at the game’s highest level points to a long-term role within the organization. His mix of innings as a starter and reliever during 2025 should provide a foundation for expanded responsibilities in the seasons ahead.