How San Diego Got Its Name: A Spanish Explorer's Tribute to Saint Didacus

The name San Diego comes from Saint Didacus of Alcalá (Spanish: San Diego de Alcalá), a 15th-century Franciscan lay brother known for his humility and care for the sick. His feast day is November 12.

On November 12, 1602, Spanish explorer Sebastián Vizcaíno sailed into the bay now known as San Diego Bay. To honor the saint's feast day, he named the harbor "San Diego". The name later extended to the presidio, mission, and the city that grew around them.

Didacus was canonized in 1588; he is a patron of the Franciscan Order and of the diocese of San Diego.