José Alberto Martínez (born July 25, 1988) is a Venezuelan professional baseball first baseman and outfielder for the Leones de Yucatán of the Mexican League.

He has previously played in Major League Baseball (MLB) for the St. Louis Cardinals, Tampa Bay Rays, and Chicago Cubs.

As a member of the Triple-A Omaha Storm Chasers in the Kansas City Royals organization in 2015, Martínez set a modern-day Pacific Coast League (PCL) record with a .384 batting average.

From 2006 to 2012, Martínez played in the White Sox organization, reaching as high as the Double-A Birmingham Barons before becoming a minor league free agent on November 2, 2012.

While playing for the Omaha Storm Chasers that year, his .384 batting average broke a modern-day Pacific Coast League (PCL) record.

[7] He batted .382 overall in 2015–which included rehab time in the Arizona League–good for the fifth-highest mark since the modern era of the minor leagues began in 1963.

[12] His first major league hit and run batted in (RBI) occurred two days later, scoring Greg Garcia on an infield single in a 12−5 loss to the Milwaukee Brewers.

[14] The Cardinals announced that Martínez made their 2017 Opening Day roster, his first in the major leagues, after leading the club with 19 hits and 15 RBI in spring training.

[16] On August 6, 2017, Martínez hit his first major league career grand slam off Homer Bailey of the Cincinnati Reds, cementing a nine run frame for the Cardinals in a 13–4 win.

On January 14, 2021, Martínez signed a one-year, split contract with the New York Mets, which includes a $1 million option if he makes the team after spring training.

[24] On March 7, 2021, Martínez suffered a torn meniscus in his left knee after colliding with an umpire trying to field a ground ball, forcing him to be out for about four months.