For Hancock's Half Hour, Hancock was paired with the script-writing team Ray Galton and Alan Simpson; with the comedian, they created one of Britain's best­ loved and enduring comic characters. The Tony Hancock of the series was a slightly snobbish type with delusions of grandeur and a talent for self-deception. The sharp scripts were complemented by the contribution of the supporting cast (Hattie Jacques, Kenneth Williams, Bill Kerr, and Sid James) and immeasurably from Hancock himself. He proved a master of comic timing, instinctively knowing how long to hold a pause for maximum effect (similar to Jack Benny in the United States). In 1956 the show transferred to BBC Television, and Hancock went on to even greater success.

     The television Hancock's Half Hour was a landmark in British television and became the yardstick by which all subsequent sitcoms were measured. On TV, many of the episodes were virtual double-handers between Tony Hancock and co-star Sid James, who appeared as a down-to-earth type, though still a shady character always with an eye on the main chance. Their partnership proved enormously popular with viewers and critics alike. On TV, Hancock displayed a marvelous talent for facial comedy; by rolling his eyes, creasing his brow in deep concentration, sucking on his lips, or puffing out his cheeks, he could suggest any number of internal wranglings. When these expressions were combined with his superb timing, he managed to wring big laughs from the thinnest of lines. But the lines were rarely thin; Galton and Simpson's writing was constantly improving, and the series, unlike many in the genre, continued to grow from strength to strength. After making 57 episodes of the TV series from July 6, 1956 to May 6, 1960, Hancock decided he wanted a change in the format. Always convinced he could do better, Hancock was rarely happy with the work he was doing. Against the advice of his writers and producer (Duncan Wood), he insisted that James be written out of the series because he thought they had fully explored the double-act potential. Finally, his position was accepted, and the series returned, now simply called Hancock, for six more episodes. To emphasize the change in format, the first episode featured Hancock alone in his room delivering a desperate rambling monologue as he struggled to pass the time.

     Against all the odds, Hancock was a roaring success, and those six episodes stand out as the highlight of Hancock's career. One in particular, "The Blood Donor," is perhaps the best-remembered episode of any British sitcom. Hancock, however, remained unimpressed and finally split with his writers Galton and Simpson, complaining they were writing his character as being too poor, too hopeless. (Intriguingly, for their next major project, the writers went even further "down market" with the rag-and-bone man sitcom Steptoe and Son.)

     Hancock never found the perfection he was seeking, and often sought solace in alcohol. After struggling to make his mark in films and other TV series, his bouts of depression deepened and eventually he committed suicide in Australia on June 25, 1968.