Jacob Timothy Bird (born December 4, 1995) is an American professional baseball pitcher for the New York Yankees of Major League Baseball (MLB). He debuted in MLB for the Colorado Rockies in 2022. Bird played college baseball for the UCLA Bruins and led the Pac-12 Conference in earned run average in 2018. The Rockies selected him in the fifth round of the 2018 MLB draft.

Bird was born in Newhall, California and raised in Valencia, California. He identifies as Jewish. His paternal grandmother was Jewish, and his mother is Catholic. He has one older brother and two younger brothers.

When Bird was eight years old, at the end of second grade, he signed his friends' yearbooks as follows: "Save this autograph for when I’m playing in the major leagues."

Bird attended West Ranch High School in Stevenson Ranch, California, pitching and playing outfield for the baseball team, and playing for the basketball team. In his senior year of high school, he pitched to a 1.55 earned run average (ERA) with 72 strikeouts and 11 walks over 58 innings. He was an All-Foothill League selection in 2014. He committed to attend the University of California, Los Angeles (UCLA) to play college baseball for the UCLA Bruins during his senior year.

Unselected in the 2014 Major League Baseball (MLB) draft, Bird enrolled at UCLA, majoring in economics. In 2016, he played collegiate summer baseball with the Falmouth Commodores of the Cape Cod Baseball League, going 3–2 with a 2.77 ERA as a starter. As a junior he was 5–5 with a 2.75 ERA. His pitching repertoire consisted of a heavy sinker that reached 94 mph, a hard slider in the 86-88 mph range, a changeup, and a curveball.

As a senior at UCLA in 2018, Bird had a 7–4 record and started 16 games, leading the Pac-12 Conference with a 2.18 ERA, and striking out 61 batters over 111+2⁄3 innings. He said: "I'm just trying to pitch contact. My stuff is pretty heavy ... which gets a lot of ground balls... (Just) let the defense do their thing." He was named All-Pac-12, Pac-12 All-Academic first team, and Academic All-America third team. Following the season, he was selected by the Colorado Rockies in the fifth round of the 2018 MLB draft.

Bird signed with the Rockies for a signing bonus of $50,000. He made his professional debut in 2018 with the Grand Junction Rockies of the Rookie-level Pioneer League, going 4–1 with a 3.38 ERA and 30 strikeouts over 26+2⁄3 innings pitched in relief. In 2019, he played with the Single-A Asheville Tourists and was named a South Atlantic League All-Star. He went 7–2 with two saves and a 3.62 ERA and 80 strikeouts in 87 innings in 40 games, tied for third-most in the league. Bird didn't pitch competitively in 2020, as the minor league season was cancelled due to the COVID-19 pandemic. He spent the off year learning about pitching analytics and body movement, which increased his fastball velocity.

Bird began the 2021 season with the Hartford Yard Goats of the Double-A Northeast, inducing a 70.9% ground ball rate. He was then promoted to the Albuquerque Isotopes of the Triple-A West in early June. Over 39 appearances between the two clubs, Bird went 6–1 with a 3.38 ERA and 59 strikeouts over 58+2⁄3 innings. He pitched as a reliever in the Arizona Fall League for the Salt River Rafters after the season, and was 0–1 with a save and a 2.84 ERA.