| Augusto Rademaker | |
| Honorific Prefix: | His Excellency Admiral |
| Honorific Suffix: | GCTE GCA |
| Office: | Member of the Brazilian Military Junta |
| Term Start: | 31 August 1969 |
| Term End: | 30 October 1969 |
| Predecessor: | Artur da Costa e Silva (as President) |
| Successor: | Emílio Garrastazu Médici (as President) |
| Alongside: | Lira Tavares, Márcio Melo |
| Office1: | Vice President of Brazil |
| Term Start1: | 30 October 1969 |
| Term End1: | 14 March 1974 |
| President1: | Emílio Garrastazu Médici |
| Predecessor1: | Pedro Aleixo |
| Successor1: | Adalberto Pereira dos Santos |
| Office2: | Other offices held |
| Suboffice2: | Minister of the Navy |
| Subterm2: | 1967–1969 |
| Suboffice3: | Minister of Transport |
| Subterm3: | 1964–1964 |
| Suboffice4: | Minister of the Navy |
| Subterm4: | 1964–1964 |
| Suboffice5: | Member of the Supreme Command of the Revolution |
| Subterm5: | 1964–1964 |
| Birth Date: | 11 May 1905 |
| Birth Place: | Rio de Janeiro,, Brazil |
| Death Place: | Rio de Janeiro,, Brazil |
| Party: | ARENA |
| Spouse: | Ruth Lair Rist |
| Children: | 6 |
| Allegiance: |  Brazil |
| Rank: | Admiral |
| Battles: | |
| Mawards: | Grand Cross of the Military Order of Aviz Grand Cross of the Military Order of the Tower and Sword, of Value, Loyalty and Merit |
Augusto Hamann Rademaker Grünewald (11 May 1905 – 13 September 1985) was a Brazilian admiral, of German and Danish descent,[1] in the Brazilian Navy. Rademaker was one of the leaders of the Military Junta (30 August 1969 – 30 October 1969) that ruled Brazil between the illness of Artur da Costa e Silva in August 1969 and the investiture ceremony of Emílio Garrastazu Médici in October of that same year, elected by fellow officer generals and confirmed by the Congress. In the same occasions Rademaker was picked and "elected" as vice president for the same term as Medici's (1969–1974).[2]
During his tenure as vice president he was awarded[3] one of Portugal's highest honors, the Grand-Cross of the Order of the Tower and Sword on 26 July 1972. Before, in his capacity as Minister of the Navy, he was awarded the Grand-Cross of the Order of Aviz, Portugal's sole order reserved for military officials.