You need a visa for São Tomé and Príncipe if you have a Mexican passport
Visa options for São Tomé and Príncipe
Electronic visitor visa
Travelers need a visa to visit Sao Tome and Principe for Business or Tourism. An eVisa is the fastest and easiest way of obtaining a visa for Sao Tome and Principe because travelers can submit their application and supporting documents online. Once the application is approved, travelers receive their eVisa confirmation electronically. A valid visa is required to board the flight. If the visa is expired or doesn’t match the traveler’s passport information, travelers will not be able to board their flight.