Following high school, Ross embarked on his professional career, getting selected by the Detroit Tigers in the fourth round of the 1999 Major League Baseball draft.

The Arizona Diamondbacks signed him to a three-year contract in December 2012, but a season-ending hip injury limited Ross to 94 games during his first year with the team.

He made his Major League debut that day, going hitless in two at bats before exiting after getting hit by a pitch in the sixth inning as the Tigers lost 9–8 to the Kansas City Royals.

[11] After he had one hit in four games, he was optioned back to Toledo on July 16 to make room for Danny Patterson, who was returning from the disabled list.

However, with Detroit desperate for bullpen help, Ross was traded to the Los Angeles Dodgers on April 1 for relief pitcher Steve Colyer.

[20] He appeared in 14 games, batting .160 with four hits (one double, no home runs) and one RBI before getting sent back down on July 14 in favor of Steve Schmoll.

[4] Ross was out of options in 2006 and made the Dodgers Opening Day roster as a backup outfielder only because of an injury to Kenny Lofton.

On April 13, he hit a tie-breaking grand slam and a three-run home run in a 13–5 victory over the Pittsburgh Pirates.

[19] He batted .500 in eight games for the Dodgers before getting designated for assignment on April 17 to make room for Óscar Robles on the roster.

After receiving a text message from his father at the beginning of May saying he would improve, Ross declared that he was restarting his season and had 10 home runs and 18 RBI in the month.

[35][36] During the month, Ross had a stretch where nine out of 10 hits were home runs, becoming the first player to have a streak of that sort since Mark McGwire in 2001.

[4] On May 14, he hit a game-tying three-run ninth inning home run against Francisco Cordero in a 10-inning, 7–6 loss to the Reds.

[37] Then, on June 7 he hit a game-winning three-run home run in the bottom of the ninth inning against Cordero to give the Marlins an 8–7 victory over the Reds.

[40] On June 12, he hit his third grand slam of the season against Brandon League to give the Marlins a 7–3 victory over the Toronto Blue Jays.

[41] Dan Uggla and he hit back-to-back solo home runs against Kevin Gregg in the ninth inning on August 2 to give the Marlins a 3–2 victory over the Chicago Cubs.

[50] However, it was later revealed that Guillén had been left off the roster after a package of human growth hormone was intercepted as it was being shipped to his house.

Henry Schulman of the San Francisco Chronicle called it a "mild surprise" that Ross did not sign at least a two-year deal.

[61] He began the season on the disabled list with a sprained right calf, but he assumed the Giants' right field job upon his return on April 20.

[65][66] On May 18, Ross hit a three-run home run with two outs in the ninth inning against Lance Cormier to give the Giants an 8–5 victory over the Dodgers.

He was supposed to provide depth off the bench, but injuries, particularly to Carl Crawford, led to him holding a starting role for the entire season.

[73] The next day, Ross hit a three-run homer in the bottom of the second inning off Matt Moore in a 6–4 victory over the Rays.

[76] His first game back, he hit a home run against Mark Buehrle over the Green Monster at Fenway Park in a 7–5 victory over the Miami Marlins.

[79] The next day, he hit a three-run home run against Addison Reed for a walk-off win against the White Sox.

[86] On August 2, he had four hits, two doubles, and three RBI, including a game-winning solo home run against Pedro Beato in a 7–6 victory over Boston.

I've been notorious for that my whole career, where I'll hit five or six in a week, where it seems like I can't miss the pitch and I feel good in the batter's box.

[81] He has been a fan favorite in his career, especially in Florida and San Francisco, where he earned the nicknames "Toy Cannon" and "Ross the Boss", respectively.

[1][2] Ross bats right-handed and throws left-handed; one of the rarest dominant bats/throws combinations in the history of Major League baseball.

The only position player in the Baseball Hall of Fame with this combination of "bats/throws" is Rickey Henderson, who, like Ross, also had stints with the Dodgers, Red Sox and Athletics.

[95] Ross and his wife, Summer,[5] live most of the year in Scottsdale, Arizona, with their three children: Hudson,[96] Haven Leigh,[97] and Harley.

His father, Kenny, played strong safety at the University of New Mexico but became a chiropractor and bull rider after undergoing three knee surgeries in college.