William Henry "Bill" Cosby, Jr. is an American comedian, actor, author, television producer, educator, musician and activist. A veteran stand-up performer, he got his start at various clubs, then landed a starring role in the 1960s action show, I Spy. He later starred in his own series, The Bill Cosby Show, in 1969. He was one of the major characters on the children's television show, The Electric Company, for its first two seasons, and created the humorous educational cartoon series, Fat Albert and the Cosby Kids, about a group of young friends growing up in the city. Cosby has also acted in a number of films.

During the 1980s, Cosby produced and starred in what is considered to be one of the decade's defining sitcoms, The Cosby Show, which aired eight seasons from 1984 to 1992, and is still seen in syndication. The sitcom highlighted the experiences and growth of an upper-middle-class African American family. He also produced the hit sitcom, A Different World, which became second to The Cosby Show in ratings. In the 1990s, he starred in Cosby, which aired from 1996 to 2000, and during the show's last two seasons, hosted Kids Say the Darndest Things.

His good-natured, fatherly image has made him a popular personality and garnered him the nickname of "America's Dad". He has been a sought-after spokesman over the years, and has endorsed a number of products, including Jell-O pudding, Kodak film, Ford, Texas Instruments, and Coca-Cola, including New Coke. In 2002, scholar Molefi Kete Asante included him in his book, the 100 Greatest African Americans.

In 1976, Cosby earned a Doctor of Education degree from the University of Massachusetts. For his doctoral research, he wrote a dissertation entitled, "An Integration of the Visual Media Via 'Fat Albert And The Cosby Kids' Into the Elementary School Curriculum as a Teaching Aid and Vehicle to Achieve Increased Learning".

After The Cosby Show went off the air in 1992, Cosby embarked on a number of other projects, including a revival of the classic Groucho Marx game show You Bet Your Life (1992–93) along with the TV-movie I Spy Returns (1994) and The Cosby Mysteries (1994). In the mid-1990s, he appeared as a detective in black-and-white film noir-themed commercials for Turner Classic Movies. He also made appearances in three more films, Ghost Dad (1990), The Meteor Man (1993); and Jack (1996); in addition to being interviewed in Spike Lee's 4 Little Girls (1997), a documentary about the racist bombing of a Birmingham, Alabama, church in 1963. Also in 1996, he started up a new show for CBS, Cosby, again co-starring Phylicia Rashād, his onscreen wife on The Cosby Show. Cosby co-produced the show for Carsey-Werner Productions. The show was based on a cynical British program called One Foot in the Grave, but Cosby lightened the humor. It centered on Cosby as Hilton Lucas, an iconoclastic senior citizen who tries to find a new job after being "downsized", and in the meantime, gets on his wife's nerves. Madeline Kahn costarred as Rashād's goofy business partner. Cosby was hired by CBS to be the official "spokesman" for the WWJ-TV during an advertising campaign from 1995 to 1998. In addition, Cosby in 1998 became the host of Kids Say the Darndest Things. After four solid seasons, Cosby was canceled. The last episode aired April 28, 2000. Kids Say the Darndest Things was also canceled the same year. Cosby continued to work with CBS through a development deal and other projects.

A series for preschoolers, Little Bill, made its debut on Nickelodeon in 1999. The network renewed the popular program in November 2000. In 2001, at an age when many give serious consideration to retirement, Cosby's agenda included the publication of a new book, as well as delivering the commencement addresses at Morris Brown College, Ohio State University, and at Rensselaer Polytechnic Institute. Also that year, he signed a deal with 20th Century Fox to develop a live-action feature film centering on the popular Fat Albert character from his 1970s cartoon series. Fat Albert was released in theaters in December 2004. In May 2007 he spoke at the Commencement of High Point University.

In the summer of 2009, Cosby hosted a comedy gala at Montreal's Just for Laughs comedy festival, the world's largest.