The National Seismological Service (Spanish: Servicio Sismológico Nacional, SSN) is a seismological organization in Mexico that studies and records earthquake activity within the country.

It is part of the Geophysics Institute at the National Autonomous University of Mexico (UNAM) and is based in Mexico City.

The SSN was founded on September 5, 1910, by the federal government as part of an international effort to monitor seismic activity.

[1] The SSN established its first nine earthquake monitoring stations were installed between 1910 and 1923, including seven that have operated continuously since as the oldest system in North America.

Currently, the SSN has 22 seismic observatories and has plans to add 11 more to its nationwide system.