John C. Reilly seems uncomfortable as he steps in front of the camera to be photographed for the cover of this magazine. But when it’s clear the photographer isn’t satisfied with Reilly’s stiff, static poses, the actor walks over to an abandoned sawhorse and lugs it into frame, straddling it like a rodeo clown. His idea works; the photographer likes the setup better and Reilly no longer looks like he’s going before a firing squad.

CLOAK AND SWAGGER  John C. Reilly has all the right leading-man moves.

Back in his trailer, where his children’s drawings and a photo of his family hang on the refrigerator, Reilly again is friendly but distant, giving short, dry answers. It’s not until he talks about his work that he loosens up. Not exactly the level of gregarity you might expect from one of Will Ferrell’s good friends—not to mention the guy who played the hilariously inept porn star Chest Rockwell in 1997’s Boogie Nights.

He’ll likely have no choice but to get over his uneasiness in the spotlight when his turn as a troubled musician in the musical biopic parody Walk Hard: The Dewey Cox Story hits theaters Friday 21. It’s the first leading role in a major studio film for this perennial supporting actor, who’s played the oafish blue-collar type in more than 45 movies over 18 years, including a sad-sack cop in Magnolia (1999), Jennifer Aniston’s clueless pothead husband in The Good Girl (2002) and, most famously, Renée Zellweger’s hangdog cuckold in Chicago (2002), which earned him an Oscar nomination for Best Supporting Actor.

Despite the number of films on his résumé, it wasn’t until 2006’s Talladega Nights that moviegoers regularly began to recognize Reilly on the street. “I have this game I play with my wife,” he says. “If someone recognizes me, we try to figure out based on the type of person they seem to be what movie they might have seen. Generally people don’t piece all of my work together. They know me from one thing and then they say, ‘You always play bad guys,’ because they’ve seen me be a bad guy…which is great to me. That means they believed I was that person.”

But how does Reilly see himself? “I consider myself kind of a lazy person,” he says, though his hectic schedule of back-to-back movies seems to contradict that notion. “But I have this reputation for being incredibly industrious and always up to something,” he says, recounting how he has been working since the age of 12, when he got his first job as a dishwasher. “I always wanted independence. I wanted to be able to travel and have my own money. I come from a family of six, so I was ready to leave my house by the time I left.”

Reilly grew up on Chicago’s Southwest Side, where he discovered acting in the high-school drama club was a good way to avoid the juvenile detention officers he knew on a first-name basis. Much to the chagrin of his father, who wanted him to go to business school, Reilly went on to study theater at the Goodman School of Drama at DePaul University and began to act with local theater companies, including Steppenwolf. Now, he makes it back a few times a year to visit family. “When my feet touch the ground in Chicago, it feels different. I feel more solidly on the ground.”