| Election Name: | 1921 Portuguese legislative election |
| Country: | Portugal |
| Type: | parliamentary |
| Ongoing: | no |
| Previous Election: | 1919 Portuguese legislative election |
| Previous Year: | 1919 |
| Next Election: | 1922 Portuguese legislative election |
| Next Year: | 1922 |
| Seats For Election: | 163 seats to the Chamber of Deputies |
| Majority Seats: | 82 |
| Election Date: | 10 July 1921 |
| Leader1: | António Granjo |
| Leader Since1: | 1919 |
| Party1: | PLR |
| Last Election1: | 55 seats |
| Seats1: | 79 |
| Seat Change1: | 24 |
| Colour1: | 2222AD |
| Leader2: | Afonso Costa |
| Leader Since2: | 1912 |
| Party2: | PD |
| Last Election2: | 86 seats |
| Seats2: | 54 |
| Seat Change2: | 32 |
| Colour2: | FF69B4 |
| Leader3: | Álvaro de Castro |
| Leader Since3: | 1920 |
| Party3: | PR |
| Last Election3: | Did not contest |
| Seats3: | 12 |
| Seat Change3: | 12 |
| Colour3: | 4a452a |
| Image4: | CM |
| Party4: | CM |
| Last Election4: | Did not contest |
| Seats4: | 4 |
| Seat Change4: | 4 |
| Colour4: | 014a94 |
| Image5: | CCP |
| Leader5: | António Lino Neto |
| Leader Since5: | 1915 |
| Party5: | CCP |
| Last Election5: | 1 seat |
| Seats5: | 3 |
| Seat Change5: | 2 |
| Colour5: | 00bfff |
| Image6: | PR |
| Party6: | PR |
| Last Election6: | Did not contest |
| Seats6: | 2 |
| Seat Change6: | 2 |
| Colour6: | ff8c00 |
| Map Size: | 300px |
| Map2 Size: | 300px |
| Prime Minister | |
| Posttitle: | Prime Minister after election |
| Before Election: | Tomé José de Barros Queirós |
| Before Party: | PLR |
| After Election: | António Granjo |
| After Party: | PLR |
Parliamentary elections were held in Portugal on 10 July 1921.[1] Prior to the elections, the Republican Union had merged with the Evolutionist Party to form the Republican Liberal Party (PLR).[2] The elections resulted in the PLR becoming the largest in Parliament, winning 79 of the 163 seats in the House of Representatives and 32 of the 71 seats in the Senate.[3]
The government that was subsequently formed lasted only a few months, as on 19 October (the "night of blood"), a military coup resulted in the deaths of several prominent conservative figures including prime minister António Granjo. New elections were held in January 1922.
| Party | House of Representatives | Senate | ||||||
|---|---|---|---|---|---|---|---|---|
| Votes | % | Seats | +/– | Votes | % | Seats | +/– | |
| Republican Liberal Party | 79 | +24 | 32 | +5 | ||||
| Democratic Party | 54 | –32 | 22 | –14 | ||||
| Reconstitution Party | 12 | New | 7 | New | ||||
| Monarchist Cause | 4 | New | 0 | New | ||||
| Catholic Centre Party | 3 | +2 | 3 | +2 | ||||
| Portuguese Socialist Party | 0 | –8 | 0 | 0 | ||||
| Regionalist Party | 2 | – | – | |||||
| Other parties and independents | 9 | – | 7 | 0 | ||||
| Invalid/blank votes | – | – | – | – | – | – | ||
| Total | 163 | 0 | 71 | 0 | ||||
| Registered voters/turnout | – | – | – | – | ||||
| align=left colspan=9 | Source: Nohlen & Stöver | |||||||