Raised in Marquette Park, a working-class area of Chicago, Illinois

Started acting in community productions at age eight

Appeared with the Organic Theatre; wrote and directed a series of monologues, "Walkin' the Boogie"

Joined Steppenwolf Theatre; appeared in "Othello" and with Eric Simonson created "A Shakespeare Sampler"

Sent a videotape of his stage work to director Brian De Palma who cast Reilly in "Casualties of War"; first of several roles in support of Sean Penn

Featured in the Penn vehicle "We're No Angels"

Had featured role in Steppenwolf production of "The Grapes of Wrath"; made Broadway debut when show moved to NYC

Appeared with Penn in the film "State of Grace"

Featured in the car-race drama "Days of Thunder"; first movie with Tom Cruise

Appeared in "The Frightening Frammis," a short film Cruise directed for Showtime's series "Fallen Angels"

Played Johnny Depp's friend in "What's Eating Gilbert Grape"

Played constable in "Dolores Claiborne"

Had lead in "Hard Eight," directed by Paul Thomas Anderson and co-starring Philip Baker Hall

Played Mitch in Steppenwolf Theatre 50th anniversary production of "A Streetcar Named Desire" in Chicago

Co-starred with Mark Wahlberg and Philip Seymour Hoffman in Anderson's "Boogie Nights"

Acted with Penn in the ensemble, "The Thin Red Line"

Made rare TV appearance on the CBS drama "Martial Law"

Reteamed with writer-director Anderson for "Magnolia" playing a sweet natured cop; also in cast were Cruise, Hall and Hoffman

Had supportng roles in "For Love of the Game" and "Never Been Kissed"

Acted opposite Hoffman in the stage revival of Sam Shepard's "True West"; during course of run, the actors alternated the leading roles; each garnered Tony nominations for Best Actor in a Play

Re-teamed with Wahlberg as one of the crew members of the fishing vessel caught in "The Perfect Storm"

Appeared in "The Anniversary Party"

Had title role in the stage musical "Marty" (July 2001 and February 2002)

Starred opposite Jennifer Aniston in the indie film "The Good Girl"; earned an Independent Spirit Award nomination for Best Supporting Actor

Cast as Julianne Moore's husband in "The Hours"

Co-starred in the Martin Scorsese-directed period drama "Gangs of New York"

Played Amos Hart, the schlubby husband of an accused murderess, in the film version of the hit Broadway musical "Chicago"; received Golden Globe and Oscar nominations for Best Supporting Actor

Starred in "Criminal" an English-language version of the Argentine hit "Nine Queens" by Fabián Bielinsky

Featured in "The Aviator," Martin Scorsese's biopic of the legendary director and aviator Howard Hughes

Cast opposite Jennifer Connelly in the thriller "Dark Water"

Cast in Robert Altman's ensemble feature "A Prairie Home Companion," based on Garrison Keilor's radio program

Cast as Ricky Bobby's (Will Ferrell) childhood friend, Cal Naughton Jr in "Talladega nights: The ballad of Ricky Bobby"

Played Molly Shannon's gun-nut neighbor in "Year of the Dog"

Played the title role in the comedy spoof, "Walk Hard: The Dewey Cox Story"; also co-wrote the theme song; earned a Golden Globe nominations for Best Actor and for Best Original Song

Co-starred with Will Ferrell as unemployed adults living with their parents in the comedy "Step Brothers"