Javier Alfonso López is a Puerto Rican professional baseball pitcher for the San Francisco Giants of Major League Baseball. He is 6 feet 5 inches tall and weighs 220 pounds. López previously pitched for the Colorado Rockies, Arizona Diamondbacks, Boston Red Sox and Pittsburgh Pirates. He is a left-handed specialist known for his sidearm delivery. He also bats left-handed. López attended the University of Virginia, earning a degree in psychology from there despite leaving early to begin his baseball career. He was selected by the Arizona Diamondbacks in the fourth round of the 1998 Major League Baseball Draft. He began his career as a starting pitcher but struggled and converted into a sidearm reliever while still in the Diamondbacks' organization. Before the 2003 season, he was selected by the Boston Red Sox in the Rule 5 Draft, but he was traded to the Colorado Rockies during spring training. He spent all of 2003 on Colorado's roster, nearly tying the franchise record for most consecutive batters retired and finishing third among major league rookies in games pitched. He struggled the next two seasons, getting claimed off waivers and later sent to the minors by Arizona in 2005.
- Born: July 11, 1977 (age 41), San Juan
- Spouse: Renee López
- Aliases: Javier Lopez
- Children: Kylan López
- Height: 6′ 4″ (1.9304m)