Despite being thought of as mercenaries by the other characters in the show, the A-Team always acted on the side of good and helped the oppressed. The show ran for five seasons on the NBC television network, from January 23, 1983 to December 30, 1986 (with one additional, previously unbroadcast episode shown on March 8, 1987), for a total of 98 episodes.

It remains known in popular culture for its cartoon-like use of over-the-top violence (in which people were seldom seriously hurt), formulaic episodes, featuring the ability to form weaponry and vehicles out of old parts, and its distinctive theme tune. The show also served as the springboard for the career of Mr. T, who portrayed the character of B. A. Baracus, around whom the show was initially conceived. Some of the show's catchphrases, such as "I love it when a plan comes together," "Hannibal's on the jazz," and "I ain't gettin' on no plane!" have also made their way onto T-shirts and other merchandise.

Although not directly referenced in the series, the name of the show comes from "A-Teams," the nickname coined for Operational Detachments Alpha (ODA) in the Vietnam War, in which war the Special Forces first fought. The US Army Special Forces still uses the term ODA for their 12-man direct operations teams.

A feature film based on the series was released by 20th Century Fox on June 11, 2010. A comic book series, A-Team: Shotgun Wedding, began March 9, 2010.

NBC Entertainment President Brandon Tartikoff pitched the series to Cannell as a combination of The Dirty Dozen, Mission Impossible, The Magnificent Seven, Mad Max and Hill Street Blues, with "Mr. T driving the car".

Initially, The A-Team was not expected to become a hit, although Stephen J. Cannell has stated that "[George Peppard] said it would be a huge hit before we ever turned on a camera". In fact, the show became a huge hit and the first regular episode, which aired after Super Bowl XVII on January 30, 1983, reached 26.4% of the television watching audience, placing fourth in the top 10 rated shows, according to the Nielsen ratings.

The A-Team revolves around the four members of a former commando outfit and current group of mercenaries. Their leader is Lieutenant-Colonel/Colonel John "Hannibal" Smith (George Peppard), whose plans tend to be unorthodox but effective. Lieutenant Templeton "Faceman" Peck (Dirk Benedict; Tim Dunigan appeared as Templeton Peck in the pilot), usually referred to simply as "Face," is a smooth-talking con-man who serves as the team's appropriator of vehicles and other useful items. The team's pilot is Captain H.M. "Howling Mad" Murdock (Dwight Schultz), who has been declared insane and resides in a Veterans Administration mental institution for the show's first four seasons. Finally, there is the team's strong man and mechanic, Sergeant First Class Bosco Albert B.A. "Bad Attitude" Baracus (Mr. T). Though never verbally revealed in the series, a patch on Hannibal's uniform in the Season 1 episode "A Nice Place To Visit" indicates they belonged to the 101st Airborne division in Vietnam, even though, in the Season 5 episode "Trial by Fire," the 101st Airborne patch is replaced by the 1st Air Cavalry Division patch.

For its first season and the first half of the second season, the team was assisted by reporter Amy Amanda Allen (Melinda Culea). She was ultimately replaced by fellow reporter Tawnia Baker (Marla Heasley) for the rest of the second season. The character of Tia (Tia Carrere), a Vietnam war orphan now living in the United States, was meant to join the Team in the fifth season, but she was replaced by Frankie Santana (Eddie Velez), who served as the team's special effects expert. Eddie Velez was added to the opening credits of the fifth season after that season's second episode.

During their adventures, the A-Team was constantly met by opposition from the military police. In the show's first season they were led by Colonel Lynch (William Lucking), but he was replaced for the second, third, and earlier fourth season by Colonel Decker (Lance LeGault) and his aide Captain Crane (Carl Franklin). Lynch returned for one episode in the show's third season ("Showdown!") but was not seen after. Decker was also briefly replaced by a Colonel Briggs (Charles Napier) in the third season for one episode ("Fire!") due to Lance LeGault being unavailable for the episode, but returned shortly after. For the latter portion of the show's fourth season, the team was hunted by General Harlan "Bull" Fullbright (Jack Ging), who would later hire the A-Team to find Tia in the season four finale, during which Fullbright was killed.

The fifth season introduced General Hunt Stockwell (Robert Vaughn) who, while serving as the team's primary antagonist, was also the team's boss and joined them on several missions. He was often assisted by Carla (Judith Ledford, sometimes credited as Judy Ledford).