Hill became an unrestricted free agent on July 1, 2007.
On July 5 Hill's agent, Lon Babby, said Hill intended to sign with the Phoenix Suns on July 11 (the first day free agents can officially sign contracts).
Hill earned $1.83 million for 2007–08 with a $1.97 million player option for the next year.
Hill was named captain along with Steve Nash.
Hill was permitted by Suns Ring of Honor member, Alvan Adams, to wear his familiar No.
33 with the Suns.
Hill adapted well to the Suns' up-tempo style, averaging double figures in points as a key role player for Phoenix in the early months of the 2007–08 season.
He played in the team's first 34 games before an emergency appendectomy on January 9, 2008, sidelined him for two weeks.
Despite being bothered by multiple injuries throughout the season, Hill had his first 70-game season since leaving Detroit, averaging 13.1 ppg, 5.0 rpg, and 2.9 apg in the process.

Playing for the Phoenix Suns in the 2008–2009 season, Hill appeared in all 82 games for the first time in his career and averaged 12.0 ppg, 4.90 rpg, and 2.3 apg, scoring 27 points and 10 rebounds in the Suns' season finale.

On July 10, 2009, the Associated Press reported that Hill decided to re-sign with the Phoenix Suns for a 2-year deal, despite an offer from the New York Knicks for the full mid-level exception and the Boston Celtics offering Hill the bi-annual exception.
 The first year of the contract is believed to be worth around $3 million with the second year at Hill's option.

In 2010 the Phoenix Suns advanced to the Western Conference Semifinals, marking Hill's first playoff series victory, and making him the first NBA player in history to win his first playoff series after 15 years in the league.
After sweeping the San Antonio Spurs 4–0, the Suns then moved to the Western Conference Finals to face the Los Angeles Lakers, but lost in six games (4-2).

In 2010, he was chosen as the tenth-smartest athlete in sports by Sporting News.

On June 8 Hill exercised his option for the 2010–11 season.
The Suns underwent two major roster changes in 2010–11.
During the pre-season teammate Amar'e Stoudemire left for New York while Hedo Türkoğlu, Josh Childress and Hakim Warrick joined the Suns; within a year they also were traded for three other players.
Hill became one of seven all-time NBA players to average 13 or more points at 38 years of age or older.
On January 15, 2011, Hill passed the 16,000 career points milestone in a win over the Portland Trail Blazers.

On December 9, 2011, Hill decided to stay with the Phoenix Suns for one year, accepting a $6.5 million contract.
By the end of the 2011–12 season, Hill had reached 17,000 career points, ending the season 78th on the all-time NBA scoring list (82nd NBA/ABA), 79th in career assists (83rd), and 66th in career steals (71st).
Hill became an unrestricted free agent on July 1, 2007. On July 5 Hill's agent, Lon Babby, said Hill intended to sign with the Phoenix Suns on July 11 (the first day free agents can officially sign contracts). Hill earned $1.83 million for 2007–08 with a $1.97 million player option for the next year. Hill was named captain along with Steve Nash. Hill was permitted by Suns Ring of Honor member, Alvan Adams, to wear his familiar No. 33 with the Suns. Hill adapted well to the Suns' up-tempo style, averaging double figures in points as a key role player for Phoenix in the early months of the 2007–08 season. He played in the team's first 34 games before an emergency appendectomy on January 9, 2008, sidelined him for two weeks. Despite being bothered by multiple injuries throughout the season, Hill had his first 70-game season since leaving Detroit, averaging 13.1 ppg, 5.0 rpg, and 2.9 apg in the process.
Playing for the Phoenix Suns in the 2008–2009 season, Hill appeared in all 82 games for the first time in his career and averaged 12.0 ppg, 4.90 rpg, and 2.3 apg, scoring 27 points and 10 rebounds in the Suns' season finale.
On July 10, 2009, the Associated Press reported that Hill decided to re-sign with the Phoenix Suns for a 2-year deal, despite an offer from the New York Knicks for the full mid-level exception and the Boston Celtics offering Hill the bi-annual exception.  The first year of the contract is believed to be worth around $3 million with the second year at Hill's option.
In 2010 the Phoenix Suns advanced to the Western Conference Semifinals, marking Hill's first playoff series victory, and making him the first NBA player in history to win his first playoff series after 15 years in the league. After sweeping the San Antonio Spurs 4–0, the Suns then moved to the Western Conference Finals to face the Los Angeles Lakers, but lost in six games (4-2).
In 2010, he was chosen as the tenth-smartest athlete in sports by Sporting News.
On June 8 Hill exercised his option for the 2010–11 season. The Suns underwent two major roster changes in 2010–11. During the pre-season teammate Amar'e Stoudemire left for New York while Hedo Türkoğlu, Josh Childress and Hakim Warrick joined the Suns; within a year they also were traded for three other players. Hill became one of seven all-time NBA players to average 13 or more points at 38 years of age or older. On January 15, 2011, Hill passed the 16,000 career points milestone in a win over the Portland Trail Blazers.
On December 9, 2011, Hill decided to stay with the Phoenix Suns for one year, accepting a $6.5 million contract. By the end of the 2011–12 season, Hill had reached 17,000 career points, ending the season 78th on the all-time NBA scoring list (82nd NBA/ABA), 79th in career assists (83rd), and 66th in career steals (71st).
Grant Hill