| Lisbon Academy of Sciences Class of Letters | |
| Native Name: | Academia das Ciências de Lisboa |
| Native Name Lang: | pt |
| Formation: | 24 December 1779 |
| Headquarters: | Lisbon, Portugal |
| Leader Title: | President |
| Leader Name: | Artur Anselmo de Oliveira Soares |
| Website: | www.acad-ciencias.pt |
The Class of Letters (Portuguese: Classe de Letras) of the Lisbon Academy of Sciences holds an official consultative role on the Portuguese language in Portugal.
It was created by the queen Maria I of Portugal, on 24 December 1779, during the Age of Enlightenment.
It is based in Lisbon. The current president of the board is Adriano Moreira.