Big Eight or Big 8 may refer to:

• Big Eight Conference, a former American college athletic association
• Big 8 Conference (California), an American college conference in the California Community College Athletic Association
• Big 8 Conference (Missouri), an American high school athletic association in Missouri
• Big Eight Conference (IHSAA), an American high school athletic association in Indiana
• WIAA Big Eight Conference, an American high school athletic association in Wisconsin

• The Big Eight, an Irish showband fronted by Brendan Bowyer
• Big 8 (Usenet), a group of Usenet newsgroup hierarchies
• Big 8 Beverages, a Canadian soft drink company
• Big Eight auditors, a group of accounting firms that have since been reduced to the Big Four
• Big Eight film studios, a group of American film studios during Hollywood's "studio system": MGM, Paramount, Warner Bros., 20th Century Fox, RKO, Columbia, Universal, & United Artists
• CKLW, a Canadian Radio station formerly known as The Big 8
• "Big Eight", a song by English reggae musician Judge Dread

• Big One (disambiguation)
• Big Two (disambiguation)
• Big Three (disambiguation)
• Big Four (disambiguation)
• Big Five (disambiguation)
• Big Six (disambiguation)
• Big Seven (disambiguation)
• Big Eight Conference (disambiguation)
• Big Ten (disambiguation)
• Big 12