Jeffrey Charles Weaver (born August 22, 1976) is an American former right-handed Major League Baseball pitcher.

In a bit of a coincidence, his younger brother, Jered, was recalled from the minor leagues and replaced Jeff in the starting rotation.

On July 5, 2006, the St. Louis Cardinals acquired Weaver from the Angels in exchange for minor leaguer Terry Evans and cash considerations.

After yielding six runs in four innings in his first start, Weaver played a key role in the Cardinals' World Series win.

Weaver started and was the losing pitcher for Game 1 of the National League Championship Series against the New York Mets on October 12, 2006.

On January 26, 2007, the Seattle Mariners signed Weaver as a free agent to a one-year deal worth $8–9 million.

It was speculated that this was a strategic move by the team to allow Weaver to take some time off and make a series of "rehab" starts with a minor league affiliate.

On July 5, Weaver signed a minor league contract with the Cleveland Indians, but did not appear in the majors with them, spending the rest of the season in AAA with the Buffalo Bisons.

Weaver signed a minor-league deal with the Los Angeles Dodgers in February 2009[6] and was assigned to the AAA Albuquerque Isotopes.

[7] On October 7, 2009, Weaver was the winning pitcher in Game One of the 2009 National League Division Series between the Dodgers and his former team, the St. Louis Cardinals.