| Country: | Brazil |
| Previous Election: | 1962 |
| Next Election: | 1970 |
| Election Date: | 15 November 1966 |
| Seats For Election: | 409 seats in the Chamber of Deputies 23 seats in the Senate |
| First Election: | yes |
| Heading1: | Chamber of Deputies |
| Party1: | National Renewal Alliance |
| Leader1: | Artur da Costa e Silva |
| Percentage1: | 63.98 |
| Seats1: | 277 |
| Party2: | Brazilian Democratic Movement |
| Colour2: |
|
| Percentage2: | 36.02 |
| Seats2: | 132 |
| Heading3: | Senate |
| Party3: | National Renewal Alliance |
| Leader3: | Artur da Costa e Silva |
| Percentage3: | 56.63 |
| Seats3: | 19 |
| Party4: | Brazilian Democratic Movement |
| Colour4: |
|
| Percentage4: | 43.37 |
| Seats4: | 4 |
Parliamentary elections were held in Brazil on 15 November 1966.[1] They were the first elections held after a military coup in 1964. In 1965 the military government of President Humberto de Alencar Castelo Branco dissolved all existing parties, and enacted a new electoral law that effectively limited the number of parties to two — the pro-government National Renewal Alliance (ARENA) and the opposition Brazilian Democratic Movement.
ARENA won a landslide victory, taking 277 of the 409 seats in the Chamber of Deputies and 19 of the 23 seats in the Senate. Voter turnout was 77.2% in the Chamber of Deputies election and 77.3% in the Senate election.[2]