At age 15, Hill and friends were participating in a soccer tournament in Park City, Utah. While on their way to a round of golf, a college student narrowly missed Hill's car and slammed into his mother's car following behind him. Hill's mother, Vicki, was killed as a result.
Hill was originally drafted by the Anaheim Angels in the 7th round of the June 2000 Draft. Hill turned down the offer, opting to attend Louisiana State University and play for the varsity Tigers baseball team. While at LSU, Hill posted a career. 335 batting average with 23 home runs and 150 RBIs.
Hill was Toronto's first draft pick (13th overall) in the 2003 MLB Draft, and he made his major league debut on May 20, 2005, after being called up from the minor leagues a day earlier as an injury replacement for Corey Koskie. Although he was brought up as a shortstop, Hill appeared as a third baseman, a designated hitter, and as a second baseman during the course of the season. He finished the 2005 season with a .274 batting average, .348 OBP, and 25 doubles in 361 at-bats. After the trade of Orlando Hudson to the Arizona Diamondbacks, Hill became the starting second baseman for the Blue Jays in 2006, but was moved back to shortstop mid-season after the demotion of Russ Adams. After experiencing defensive struggles at shortstop, he was then moved back to second base, with John McDonald taking over at shortstop.
On April 4, 2008, Hill agreed to a four-year, $12 million deal that included a club option that could have run through the 2014 season. The contract would have been worth as much as $38 million if Toronto kept Hill in the fold for all seven years of the deal.
On May 29, Hill suffered a Grade II concussion in a collision with teammate David Eckstein during a game against the Oakland Athletics. Hill missed the remainder of the season.
Hill returned from his concussion during spring training. On July 5, 2009, Hill was selected by managers and players to take part in the 2009 MLB All-Star Game in St. Louis. Hill finished the 2009 season with 37 doubles, 36 home runs, 108 runs batted in, and a batting average of .286.
Prior to the first game of the 2011 season, the Blue Jays announced that they had declined the three option years on Hill's contract. Hill was placed on the 15-day disabled list on April 24, retroactive to April 20, with a strained hamstring.
On August 23, 2011, Hill and John McDonald were traded to the Arizona Diamondbacks in exchange for second baseman Kelly Johnson. Hill hit his first home run as a Diamondback on August 28 against the San Diego Padres, a two-run shot to right field off starter Cory Luebke.
In Game 4 of the 2011 NLDS, Hill hit his first postseason home run. The Diamondbacks would, however, lose the division series to the Milwaukee Brewers in 5 games.
After the 2011 season, the Diamondbacks resigned Hill to a 2-year, $11 million contract extension.
On April 7, 2012, Hill, who got moved up in the order to the #2 spot, went 2-4 with 3 RBI and 2 home runs against the Giants in the 1st and 2nd innings, both off of Madison Bumgarner. This came after going 0-4 on Opening Day while hitting 8th. The D-Backs went on to win 5-4.
On June 18, 2012, Hill hit for the cycle against the Seattle Mariners.
On June 29, 2012, Hill again hit for the cycle against the Milwaukee Brewers, becoming the first player to hit for the cycle twice in one season since Babe Herman in 1931 for the Brooklyn Robins and the first modern-era player to do so consecutively (John Reilly hit cycles a week apart in 1883).