Jered David Weaver (born October 4, 1982) is an American former professional baseball starting pitcher. He played in Major League Baseball (MLB) for the Los Angeles Angels and San Diego Padres. Weaver was drafted in the first round (12th overall) in the 2004 Major League Baseball draft by the Angels out of Long Beach State. He was a three-time All Star, and twice led the American League in wins. He is the younger brother of former pitcher Jeff Weaver.

Weaver grew up in Simi Valley, California, and attended Simi Valley High School.

Weaver attended college at California State University, Long Beach. Weaver went 37–9 during his baseball career at Long Beach State. In his final season of 2004, he became the top pro pitching prospect in the country, going 15–1, with a 1.62 earned run average (ERA), 213 strikeouts and just 21 walks in 144 innings. After the 2004 season, he won the Golden Spikes Award as the top amateur baseball player in America, the Dick Howser Trophy as the national collegiate baseball player of the year, the Roger Clemens Award as college baseball's top pitcher, and was named starting pitcher on the All-American first team by Baseball America. A 2004 Los Angeles Times called him dominating, describing his pitching as overwhelming "batters with a fastball between 89 and 94 mph, a sharp slider and an improving curveball all thrown with the same three-quarter arm delivery. He also has a fiery streak that is revealed with a fist pump or yell after a strikeout that ends an inning or a long at-bat." The article compared him to 2001 college pitching sensation Mark Prior.

In recognition of his college career, Weaver in his Long Beach uniform was the cover athlete of MVP 07: NCAA Baseball. Since it was released after he entered the major leagues, he and his likeness were not included in the game.

Weaver was originally speculated to be one of the top three overall draft picks in 2004; however, the bonus demands of his agent, Scott Boras, turned off several teams. On draft day, Baseball America asked "Where In The World Is Jered Weaver Going? That is the $10.5 million question. No team is claiming him as a possible first-round pick, and there's no sense that a club is lying in the weeds on him. He and adviser Scott Boras don't seem to be backing down from a reported desire for Mark Prior money, and he could slide through the entire first round altogether." Weaver was drafted in the 1st round (12th pick overall) by the Angels in the 2004 Major League Baseball draft. The Angels scouting director Eddie Bane said he did not know until two minutes before the draft that he'd definitely get the opportunity to choose Weaver. Bane told Baseball America about their scouting, "We did our homework. We started when Jered first got to Long Beach. I watched him in intrasquad games back in January. All our guys had seen him. We didn't back off because of reports in the paper. We do our stuff privately. We were prepared if he was there at 12 to take him." However, negotiations did not proceed smoothly. Talks broke down multiple times. Boras and client Weaver held out until the last minutes before the May 2005 deadline, becoming the longest holdout in draft history. Weaver received a $4 million signing bonus, less than the $10.5 million originally sought and also less than a $7–8 million range mentioned in the media just months before signing.

Weaver's ascent to the major leagues was quick. He made his MLB debut on May 27, 2006, a total of just 361 days after signing with the club. He spent just over one month in Single-A before being promoted to Double-A where he would finish 2005 3–3 with a 3.98 ERA. In 2006, Weaver moved up to Triple-A Salt Lake where he dominated hitters. MiLB wrote of Weaver's success, "It's fairly common for prospects to struggle in their first exposure to Triple-A ball, but the 23-year-old Weaver dominated the Pacific Coast League almost immediately, posting a 6–1 record with a 2.10 ERA in 12 games for the Bees." Angels management were impressed enough to call Weaver up when ace Bartolo Colón was on the disabled list.

He made his MLB debut on May 27, 2006, starting against the Baltimore Orioles. He pitched seven shutout innings, striking out five, and earned the victory. This was followed with three more consecutive victories. Despite his success, when Bartolo Colón returned from the disabled list, Weaver was bumped out of the rotation and sent back down to the minors. He was recalled to the majors on June 30, 2006, when the Angels designated Weaver's brother Jeff for assignment.

Weaver continued his impressive performance, at one point lowering his ERA to 1.12 after six starts. He won his first nine decisions at the start of his major league career, tying the American League record set by Whitey Ford in 1950. Weaver recorded his first loss on August 24, 2006, when he lost to the Boston Red Sox, despite allowing only one earned run in seven innings pitched, a home run to David Ortiz. He finished the season with an 11–2 record and a 2.56 ERA and placed fifth in the American League Rookie of the Year Award voting.