In February 2008, Kinsler signed a five-year deal worth $22 million guaranteed. It will jump to $32 million if the Rangers exercise their $10 million option for 2013. He received a raise to $500,000 in 2008, and a $1 million signing bonus. The contract went to $3 million in 2009, $4 million in 2010, $6 million in 2011, and $7 million in 2012. If the Rangers were to choose not to exercise their $10 million option, Kinsler was to receive a $500,000 buyout. If he were traded, both the buyout and the option year were to increase by $500,000. If the option were exercised, the commitment would have been the largest the Rangers have ever made to a player whom they drafted and developed. "Ian represents the past, present, and future of this organization", said assistant general manager Thad Levine.
Kinsler was delighted when Rangers manager Ron Washington ultimately committed to Kinsler being the team's leadoff hitter in 2008. "I didn't think he was the prototype leadoff hitter, but the guy proved me wrong", Washington said. "He'll take a walk, or get one run for us with one swing of the bat. He can bunt, he can run, and he can hit the ball to the other side."
Through mid-May 2008, Kinsler had the best career stolen-base percentage (88.5%) of anyone in Rangers/Senators history with at least 40 attempts. "It's part of my game", said Kinsler. "It's not one of the first things I'm known for." According to scouts, his ability on the basepaths is due to innate instincts and his "twitch speed" rather than his pure running speed. Grouse, who signed him, says that Kinsler also "goes from first to third faster than anyone, because he has that God-given ability to read the ball so well off the bat."
In 2008, despite missing the last six weeks of the season, Kinsler was third in the AL in times advanced from first to third on a single (17), fourth in batting average (.319) and power/speed number (21.3), fifth in steals of third base (8) and "bases taken" (23; advanced on fly balls, passed balls, wild pitches, balks, etc.), sixth in line drive percentage (24%) and in extra base hit percentage (10.8% of all plate appearances), eighth in runs (102) and OPS (.892), ninth in sacrifice hits (8) and home runs on the road (14), and tenth in stolen bases (26; while only being caught twice—a 93% success rate) and lowest strikeout percentage (11.5% of at bats).
Kinsler, who is Jewish, and whose father is Jewish while his mother is Catholic, has become a prominent figure in the Jewish community, and enjoys the attention that he attracts from it. He was featured in the 2008 Hank Greenberg 75th Anniversary edition of Jewish Major Leaguers Baseball Cards, licensed by Major League Baseball, commemorating the Jewish major leaguers from 1871 through 2008. He joined, among others, teammate Scott Feldman, Brad Ausmus, Kevin Youkilis, Ryan Braun, Gabe Kapler, Jason Marquis, Jason Hirsh, John Grabow, Craig Breslow, and Scott Schoeneweis. Kinsler was one of three Jewish players in the 2008 All Star Game, joining Youkilis and Braun. He says that "Youkilis will always say something to me on the bases [referring to the fact that they are both Jewish]. 'Happy Passover,' he'll throw something at me." In 2013 he passed Shawn Green with his 163rd steal, to become the all-time career steals leader among Jewish major leaguers. Through the 2019 season, his 243 steals led the career all-time list of Jewish major leaguers (directly ahead of Ryan Braun), his 416 doubles placed him second directly behind Shawn Green, his 257 home runs and 909 RBIs both placed him 4th (behind Green and Braun), his 693 walks placed him 4th behind Sid Gordon, and his 41 triples placed him 6th behind Gordon. His 31 steals in 2009 were the third-most ever in a season by a Jewish ballplayer, behind the 35 steals by Shawn Green in 1998 and the 33 steals by Ryan Braun in 2011.
In 2008 Kinsler won the Rangers' Jim Sundberg Community Achievement Award, in recognition of his having devoted a great deal of his personal time to the community.