Assembleia Nacional is a Portuguese expression meaning National Assembly. It may refer to:
- National Assembly of Angola (Assembleia Nacional de Angola)
- National People's Assembly of Guinea-Bissau (Assembleia Nacional Popular da Guiné-Bissau)
- National Assembly of São Tomé and Príncipe (Assembleia Nacional de São Tomé e Principe)
- Assembleia Nacional, the Portuguese legislature during the Estado Novo.