In 1959, at the age of 22, Landon began his first starring TV role as Little Joe Cartwright on Bonanza, one of the first TV series to be broadcast in color.
Also starring on the show were Lorne Greene, Pernell Roberts, and Dan Blocker.
During Bonanza's sixth season (1964–1965), the show topped the Nielsen ratings and remained number one for three years.

Receiving more fan mail than any other cast member, Landon negotiated with executive producer David Dortort and NBC to write and direct some episodes.
In 1962, Landon wrote his first script.
In 1968, Landon directed his first episode.
In 1993, TV Guide listed Little Joe's September 1972 two-hour wedding episode ("Forever") as one of TV's most memorable specials.
Landon's script recalled Little Joe's brother, Hoss, who was initially the story's groom, before Dan Blocker's death.
During the final season, the ratings declined, and NBC canceled Bonanza in November 1972.
The last episode aired on January 16, 1973.

Along with Lorne Greene and Victor Sen Yung, Landon appeared in all 14 seasons of the series.
Landon was loyal to many of his Bonanza associates including producer Kent McCray, director William F. Claxton, and composer David Rose, who remained with him throughout Bonanza as well as Little House on the Prairie and Highway to Heaven.
In 1959, at the age of 22, Landon began his first starring TV role as Little Joe Cartwright on Bonanza, one of the first TV series to be broadcast in color. Also starring on the show were Lorne Greene, Pernell Roberts, and Dan Blocker. During Bonanza's sixth season (1964–1965), the show topped the Nielsen ratings and remained number one for three years.
Receiving more fan mail than any other cast member, Landon negotiated with executive producer David Dortort and NBC to write and direct some episodes. In 1962, Landon wrote his first script. In 1968, Landon directed his first episode. In 1993, TV Guide listed Little Joe's September 1972 two-hour wedding episode ("Forever") as one of TV's most memorable specials. Landon's script recalled Little Joe's brother, Hoss, who was initially the story's groom, before Dan Blocker's death. During the final season, the ratings declined, and NBC canceled Bonanza in November 1972. The last episode aired on January 16, 1973.
Along with Lorne Greene and Victor Sen Yung, Landon appeared in all 14 seasons of the series. Landon was loyal to many of his Bonanza associates including producer Kent McCray, director William F. Claxton, and composer David Rose, who remained with him throughout Bonanza as well as Little House on the Prairie and Highway to Heaven.
Michael Landon