The 1965-1966 television season is the 20th network season in the United States television history. It began on Sunday, September 5, 1965 and ended on Sunday, May 29, 1966. The effective start date of the 1965-66 season for the purposes of audience measurement was September 5, 1965 through September 3, 1966.
Universe estimates used to calculate a program or network's rating within that particular demographic for the 1965-66 television season.
| Demographic | Population | Share |
|---|---|---|
| Households | 53,850,000 | |
| Persons 2+ | 178,782,000 |