Will you be rooting alongside St. Louis Cardinals fanatics Jon Hamm, Jenna Fischer, and John Grisham? Or with Owen Wilson, George W. Bush, and the Texas Rangers? See the famous fans of the two teams as they head to the World Series. In 2009, Mad Men star Jon Hamm got to live out a boyhood dream when the All-Star Game was held in his native St. Louis—he played in a celebrity softball game at Busch Stadium with the Wizard of Oz himself, Ozzie Smith. “Oh, my God, I've always been a huge Cardinals fan," Hamm gushed to the New York Daily News. "I remember going to the World Series in '82, '85, and '87, and this is amazing. The fact that the All-Star Game is in St. Louis and that I'm playing here this week, it's all pretty cool. I would have come for the game anyway." Michael Buckner / Getty Images To research his role as a Major League reliever in 2010’s How Do You Know, Dallas native Owen Wilson spent time at spring training with the Texas Rangers. “I got here yesterday around 9:30, and I guess by 10 a.m. I had it,” Wilson, who hung out with pitchers Eddie Guardado and C. J. Wilson, told the Dallas Morning News. “Those are the two lefties, and I’m a lefty. We’ve got to stick together.” Guardado welcomed the Hollywood rookie, who threw out a first pitch for the team in 2005. "We'll teach him a few things," Guardado said. "We'll teach him how to chew the bubblegum, spit the seeds and hold the cup." Tony Gutierrez / AP Photo Growing up in St. Louis, The Office’s Jenna Fischer was such a big Cardinals fan that she even wrote a poem about the team during its 1982 World Series appearance. When asked to recite it during the 2009 All-Star Game in St. Louis, though, Fischer balked. “I feel like it was 'Roses are red, violets are blue, Cardinals ... something,'” she told Yahoo Sports. Fischer also admitted that being in Los Angeles for so long has divided her baseball loyalty. “I'm a big Dodgers fan too because I've lived there for 13 years,” she confessed. “I guess I say that I'm a Dodgers fan unless they're playing the Cardinals, and then my heart is with St. Louis.” Dilip Vishwanat / Getty Images George W. Bush is more than just a Texas Rangers fan; he once owned the team and was its managing general partner for five years, until he became governor of the state. Bush even used his baseball experience to deflect a question while running for president in 2000. When asked what his biggest mistake as an adult was, he replied, “Well, I signed off on that wonderful transaction, Sammy Sosa for Harold Baines …” The 43rd president, who frequently sits with current owner Nolan Ryan, also helped set a Guinness World Record at Rangers Ballpark this summer for most people wearing sunglasses in the dark. David J. Phillip / AP Photo Being linked to his hometown is such an integral part of Nelly’s identity that his hip-hop group is known as the St. Lunatics. And when ESPN asked the former baseball star whether he’d rather have a Grammy or a World Series ring, he didn’t hesitate: “Oh, a championship ring,” Nelly said. “Definitely. Preferably a World Series ring with the Cardinals.” James A. Finley / AP Photo Though he once managed the Bad News Bears, Billy Bob Thornton has bled Cardinal red since he was a boy. As Thornton explained to Sports Illustrated in 2005, “The farm club for the Cardinals, the Arkansas Travelers, played in Little Rock, where I grew up. I saw a lot of people coming through there. Keith Hernandez. Jose Cruz. We were just all Cardinals fans because we didn't have our own major league team, so St. Louis was the closest one to us, and our farm club was there. Everybody in Arkansas is a Cardinals fan.” Dilip Vishwanat / Getty Images After leading the Dallas Mavericks to their first NBA championship in 2011, Dirk Nowitzki was given the honor of throwing out a first pitch at a Rangers game this summer. “It's always great to be here,” Nowitzki, who toyed with tossing a basketball from the mound instead of a baseball, told ESPN. “I'm a Ranger fan. I came out last year to support them in their run to the playoffs, and they unfortunately came up a little short like we did in '06. Hopefully one day they'll be back on that stage and get it done.” Tony Gutierrez / AP Photo When the Texas Rangers were up for sale in 2009, Dallas Cowboys legend Roger Staubach explored becoming an owner. In the end, Nolan Ryan assumed control of the team, but he invited the Hall of Fame quarterback to throw out the first pitch on opening day of the 2010 season. "My arm is in good shape, so I won't have any excuses," Staubach told ESPN, adding, “I want to throw it a little better than Barack Obama." When it was over, even the Ryan Express was impressed with Staubach’s fastball. The Hall of Fame pitcher called it one of the "best first pitches" he's ever seen and thought Staubach was "holding back." LM Otero / AP Photo While in junior college, John Grisham gave up his dream to play professional baseball, but he never lost his love for the St. Louis Cardinals. His autobiographical 2001 novel A Painted House even features a 7-year-old cotton farmer who is saving up his money just to buy a Cardinals jacket. The book helped Grisham become friends with St. Louis manager Tony La Russa. “After he read A Painted House, which was full of Cardinals baseball, Tony invited me to throw out the Opening Day first pitch,” Grisham told Sports Illustrated in 2007. “I got there and he said, ‘John, Will Clark is throwing the pitch. Can you catch it?’ I said, ‘Catching in front of 45,000 people is harder than throwing.’ But I got through it.” Joe Ellis / AP Photo Country singer Gretchen Wilson takes almost as much pride in being a “Redneck Woman” as she does in being a Redbird fan. In fact, when the Cards made it to the 2004 World Series, Wilson rewrote the lyrics to her trademark song and released “Redbird Fever.” Though the Red Sox swept St. Louis, Wilson’s anthem will likely get some airplay again this year. As she sings: “There's other teams out there, and yeah, they can play / But a Cardinal fan is proud and loud until our dying day / We drink cold beer and eat hot dogs on the bleachers in the sun / No, I don't need no other fan 'cause the Cards are #1 / Some people think we're crazy, but Redbird fans are true / 'Cause in this Cardinal Nation we're all winners through and through.” Rich Pilling, MLB Photos / Getty Images