B
- Chantal Bailey, Olympic Speedskater
- Bob Balaban, actor and director
- Adam Baldwin, actor, voice actor, blogger, Chuck, Jackie Chan Adventures, The Cape
- Paris Barclay, Emmy-winning and DGA Award-winning TV director, In Treatment, NYPD Blue, Cold Case
- John Bardeen (1908–91) winner of two Nobel Prizes in Physics
- Brandon Barnes, rock musician in the band Rise Against
- John Barrowman, actor, singer, dancer
- Peter Bartlett, actor, One Life to Live, The Princess and the Frog
- Hank Bauer (1922–2007), right fielder and manager with the New York Yankees and Kansas City Athletics; also a decorated World War II U.S. Marine
- Jennifer Beals, actress, The L Word, The Chicago Code, The Book of Eli
- Edward Beecher, theologian and abolitionist
- Darryl M. Bell, actor, A Different World, Homeboys in Outer Space
- Josh Bell, third baseman for the Baltimore Orioles
- Saul Bellow, Nobel Prize and Pulitzer Prize-winning writer
- Louis Bellson, jazz drummer, bandleader and musician
- James Belushi, actor, comedian, According to Jim, Saturday Night Live, The Defenders
- Vincent Hugo Bendix, inventor, industrialist and pioneer in both the automotive and aviation industries
- Jack Benny, actor and comedian
- Jodi Benson, actress, voice actress, and soprano singer, The Little Mermaid
- Tom Berenger, actor, Platoon
- Emily Bergl, actress, Men in Trees
- Shelley Berman, comedian, actor, Curb Your Enthusiasm, Boston Legal, Meet the Fockers
- Joseph Bernardin (1928–96), Cardinal Archbishop of the Archdiocese of Chicago
- Edward Allen Bernero, TV writer, producer, and director, co-creator of Third Watch
- Black Hawk, Sauk Indian Chief
- Edwin Black, syndicated columnist, journalist, author of IBM and the Holocaust
- Quincy Black, linebacker for the Tampa Bay Buccaneers
- Zach Blair, musician Rise Against
- Rosa Blasi, actress, Strong Medicine, Make It or Break It, Hitz
- Robert Bloch, writer, author of Psycho
- Sidney Blumenthal, journalist, aide to President Bill Clinton
- Michael Boatman, actor, writer, Spin City, China Beach, Arliss
- Samuel Bodman, politician (Republican), U.S. Secretary of Energy, Deputy Secretary of the U.S. Treasury Department
- Eric Bolling, anchor at the Fox Business Network, co-host of The Five
- Lou Boudreau, (1917–2001) Hall of Fame baseball player
- Michael Bowden, pitcher for the Boston Red Sox
- Bruce Boxleitner, actor, science fiction novelist, Babylon 5, Scarecrow and Mrs. King, the Tron films
- Lara Flynn Boyle, actress, The Practice, Twin Peaks, Men in Black II
- Lydia Moss Bradley, philanthropist and founder of Bradley University
- Mark Staff Brandl, art critic, reviewer for Art in America
- Mac Brandt, actor, Prison Break
- Andre Braugher, actor, Homicide: Life on the Street, Hack, Men of a Certain Age
- Tamara Braun, soap opera actress
- Wendy Braun, actress, General Hospital
- Anthony Braxton, jazz
- Josh Brent, nose tackle for the Dallas Cowboys
- Paul Brittain, actor, comedian, cast member on Saturday Night Live
- David Broder, journalist, author, Washington Post columnist
- Phil Brooks, professional wrestler and current WWE Champion under the ring name "CM Punk"
- Patrick Brown, offensive tackle for the Minnesota Vikings
- Sergio Brown, safety for the Indianapolis Colts
- Shannon Brown, guard for the Phoenix Suns
- Tony Brown, former NBA player and current assistant coach for the Dallas Mavericks
- William Jennings Bryan, politician (Democrat), lawyer, US Secretary of State
- Bob Bryar, musician My Chemical Romance Drummer
- John Carl Buechler, horror movie writer/director and special effects artist
- Bryan Bulaga, offensive tackle for the Green Bay Packers
- Richard Bull, actor, Little House on the Prairie, Voyage to the Bottom of the Sea
- Daniel H. Burnham, architect
- Heather Burns, actress, Bored to Death, Miss Congeniality and its sequel
- Drew Butera, catcher for the Minnesota Twins
- Dick Butkus, Hall of Fame linebacker for the Chicago Bears
- Will Bynum, point guard for the Detroit Pistons
- Tim Byrdak, relief pitcher for the New York Mets
Read more about this topic: List Of People From Illinois