If you have ever looked at a map of Southern California, you may have wondered: why is San Diego called San Diego? The name sounds warm, sunny, and very Spanish. Many people think it is just a nice nickname. But San Diego is not a nickname at all. It is the city’s official legal name. And the reason behind it goes back more than 400 years.
The story includes Spanish explorers, sailing ships, a Catholic saint, and the first mission in California. Let’s follow the name from Spain to the Pacific coast.
Short Answer
Why is San Diego called San Diego? San Diego is named after Saint Didacus of Alcalá, a Spanish Franciscan lay brother. Explorer Sebastián Vizcaíno renamed the bay “San Diego” in 1602 to honor the saint. The mission and later city kept the name. It means “Saint Diego” in English.
Quick Facts at a Glance
| City | San Diego |
|---|---|
| State / Country | California, United States |
| Nickname | America’s Finest City (but “San Diego” is the official name, not a nickname) |
| Literal Meaning | Saint Didacus / Saint Diego |
| First Known Usage | 1602, for San Diego Bay |
| Popularized By | Spanish explorers, missionaries, and mapmakers |
| Known For | Beaches, San Diego Zoo, Balboa Park, U.S. Navy, Mission San Diego de Alcalá |
What Does “San Diego” Mean?
“San” is the Spanish word for “saint.” “Diego” is the Spanish form of the older Latin name “Didacus.” So San Diego means Saint Didacus, or Saint Diego in English.
Who was Saint Didacus? He was a Franciscan lay brother who lived in Spain in the 1400s. A lay brother is a religious brother, not a priest. He was known for being humble and for caring for sick people. He died in 1463. The Catholic Church officially made him a saint in 1588.
This is important because many California city names come from Spanish saints and missions. You can see more examples on our guide to California city nicknames.
Why Is San Diego Called San Diego?
So why is San Diego called San Diego? The name came from a Spanish explorer’s decision in 1602. But before that, the bay had a different name.
In 1542, Juan Rodríguez Cabrillo became the first European to enter the bay. According to the National Park Service, Cabrillo named it San Miguel. He claimed the area for Spain, but he did not stay or build a settlement.
Sixty years later, Sebastián Vizcaíno arrived. The viceroy of New Spain sent him to explore and map the California coast. Vizcaíno entered the bay in November 1602. According to Encyclopaedia Britannica, he renamed it San Diego de Alcalá. He did this to honor Saint Didacus of Alcalá.
There is a small historical puzzle here. Vizcaíno’s expedition flagship also carried the name San Diego. So some historians believe the bay may have been named directly for the ship, the saint, or both. The simplest explanation is that both the ship and the bay go back to the same saint.
The name stuck. More than 160 years later, Spanish settlers and missionaries returned. In 1769, Father Junípero Serra and Captain Gaspar de Portolá founded Mission San Diego de Alcalá. It was the first California mission. The nearby settlement and later the city kept the same name. San Diego became a city in 1850.
Origin of the Name: Not Really a Nickname
Many city nicknames grow slowly over time. San Diego is different. It has a clear start. It was a Spanish Christian name given to a bay. It is not a casual nickname like “America’s Finest City.” It is an official place name with religious roots.
If we ask who coined the name, the best answer is Sebastián Vizcaíno. But he did not create a new word. He used the name of a well-known Catholic saint.
Who Coined the Name?
Sebastián Vizcaíno is usually credited with giving San Diego its name. He was a Spanish explorer and merchant. In 1602, he led an expedition to explore the California coast. He renamed the bay San Diego de Alcalá.
No historian knows for certain whether Vizcaíno chose the name because of the saint’s feast day, because his ship was named San Diego, or both. The most likely answer is both. The ship was named after the saint, and the bay received the same holy name.
You do not need a single person to explain a city name when it comes from a saint. The name began with a religious tradition, not a marketing campaign.
History Behind the Name
Long before Spanish ships arrived, the Kumeyaay people lived in the San Diego area. They had their own villages, food traditions, and place names.
In 1542, Juan Rodríguez Cabrillo became the first European to see the bay. He named it San Miguel and claimed the land for Spain. He did not stay long.
In 1602, Sebastián Vizcaíno arrived. He spent about ten days in the bay. He praised the harbor and renamed it San Diego de Alcalá. His reports later encouraged Spain to send settlers to Alta California.
In 1769, Spain began colonizing Alta California. Father Junípero Serra and Captain Gaspar de Portolá traveled north from Baja California. They established a presidio and Mission San Diego de Alcalá. The Mission Basilica San Diego de Alcalá explains that this was the first of the 21 California missions.
After Mexico won independence from Spain in 1821, San Diego became part of Mexico. After the Mexican-American War, California became part of the United States in 1848. San Diego was incorporated as a city in 1850. The old Spanish name stayed. It had already appeared on maps, mission records, and official documents for centuries.
Timeline: How San Diego Got Its Name
| Year | Event |
|---|---|
| 1542 | Juan Rodríguez Cabrillo enters the bay and names it San Miguel. |
| 1602 | Sebastián Vizcaíno renames the bay San Diego de Alcalá. |
| 1769 | Mission San Diego de Alcalá is founded as the first California mission. |
| 1821 | Mexico gains independence from Spain. San Diego becomes part of Mexico. |
| 1848 | California becomes part of the United States after the Mexican-American War. |
| 1850 | San Diego is incorporated as a city. |
How the Name Spread and Stuck
The name San Diego did not become popular because of a tourism campaign. It spread because Spain used it on official maps and church records. Missionaries wrote it again and again. Soldiers and settlers repeated it. By the 1800s, San Diego was simply the name everyone used.
Later, railroads, newspapers, and land developers used the name. The city grew after the 1880s and 1900s. Tourism campaigns later focused on the nickname “America’s Finest City,” not on the name San Diego itself. The official name was already strong.
To learn about that tourism nickname and others, see the full San Diego nicknames guide.
Myths vs. Facts
| Myth | Reality |
|---|---|
| San Diego was named after a Spanish king or explorer named Diego. | It was named after Saint Didacus of Alcalá, a Catholic saint. No Spanish king founded the city. |
| Juan Rodríguez Cabrillo named the city San Diego. | Cabrillo named the bay San Miguel in 1542. Vizcaíno renamed it San Diego in 1602. |
| Father Junípero Serra invented the name. | Serra founded the mission in 1769, but the bay already had the name San Diego from 1602. |
| San Diego is just a nickname. | San Diego is the city’s official legal name. “America’s Finest City” is its famous nickname. |
Is the Name Still Used Today?
Yes. San Diego appears on every city document, map, highway sign, and airport sign. Locals say San Diego. The government uses it. No serious movement has ever tried to change it.
Tourism groups use the name alongside “America’s Finest City.” But “San Diego” remains the formal name on legal records.
Cultural Impact
The name San Diego shows up all over local life.
The San Diego Padres baseball team is one example. “Padres” comes from the Spanish word for fathers or priests. It is a direct nod to the city’s mission history.
Mission San Diego de Alcalá still stands as a Catholic parish and historic landmark. Schools, universities, and public buildings carry the name. San Diego State University, UC San Diego, and San Diego International Airport all use it.
Movies and television shows set in the area often say the name in a way that feels sunny and relaxed. The name itself has become part of the city’s brand.
Interesting Facts
- San Diego Bay was first called San Miguel by Cabrillo in 1542.
- Saint Didacus was canonized in 1588, only 14 years before Vizcaíno arrived.
- Mission San Diego de Alcalá was the first of 21 California missions.
- “San” means saint. “Diego” comes from the Latin name Didacus.
- The name survived three governments: Spain, Mexico, and the United States.
- Vizcaíno’s expedition flagship may have carried the name San Diego, tying the ship and the bay together.
- San Diego became a city in 1850.
- The city’s baseball team, the Padres, is named after Spanish mission priests.
- San Diego’s official nickname, “America’s Finest City,” is much younger than the name San Diego itself.
- The city name has religious roots, not military or royal roots.
Other Nicknames of San Diego
San Diego has other nicknames too. The most famous is “America’s Finest City.” People also say “Daygo” as a casual short form. Some older promotional names include “City in Motion.”
These are fun, but they are not the official city name. If you want the full list, explore the San Diego nicknames pillar page.
Comparison: San Diego vs. Los Angeles
San Diego and Los Angeles both have Spanish names with Catholic roots. But they mean different things.
| Feature | San Diego | Los Angeles |
|---|---|---|
| Name meaning | Saint Didacus | The Angels |
| Language origin | Spanish | Spanish |
| First Spanish naming | 1602 | 1781 |
| Still official name? | Yes | Yes |
Los Angeles grew from a later Spanish settlement called El Pueblo de Nuestra Señora la Reina de los Ángeles. That is why people call it the City of Angels. You can read more about that story in our Los Angeles nicknames guide.
Related City Nicknames
Frequently Asked Questions
What does San Diego mean in English?
San Diego means Saint Didacus or Saint Diego. “San” is Spanish for saint. “Diego” is the Spanish version of the Latin name Didacus. The city is named after Saint Didacus of Alcalá, a Spanish Franciscan lay brother.
Why did Sebastián Vizcaíno name it San Diego?
Vizcaíno renamed the bay San Diego de Alcalá in 1602 to honor Saint Didacus of Alcalá. His expedition flagship also carried the name San Diego. The bay, the ship, and the later city all trace back to the saint.
Who was Saint Didacus of Alcalá?
Saint Didacus was a Spanish Franciscan lay brother who lived in the 1400s. He cared for sick people and was known for humility. He died in 1463 and was canonized by the Catholic Church in 1588.
Was San Diego always called San Diego?
No. In 1542, Juan Rodríguez Cabrillo first named the bay San Miguel. It became San Diego de Alcalá in 1602 when Sebastián Vizcaíno renamed it. The city later kept the San Diego name.
Is San Diego an official city name or a nickname?
San Diego is the official legal name of the city. It is not a nickname. The city’s best-known nickname is “America’s Finest City.”
What was San Diego called before 1602?
Before 1602, the bay was called San Miguel. Juan Rodríguez Cabrillo gave it that name in 1542. The name did not stick because Spain did not settle the area at that time.
Did Father Junípero Serra name San Diego?
No. Father Serra founded Mission San Diego de Alcalá in 1769, but he did not create the name. The bay had been called San Diego since 1602. The mission adopted the existing name.
Is San Diego named after a ship?
Partly. Vizcaíno’s expedition flagship was named San Diego. The ship itself was named after Saint Didacus. So the bay, the ship, and the city all share the same saintly origin.
When did San Diego become a city?
San Diego was incorporated as a city in 1850. That was after California became part of the United States. The Spanish name stayed because it had already been used for centuries.
What are San Diego’s other nicknames?
San Diego is often called “America’s Finest City.” Locals sometimes shorten it to “Daygo.” Older promotional nicknames include “City in Motion.” You can explore them all in the San Diego nicknames guide.
Explore More
Conclusion
Now you know why San Diego is called San Diego. The name comes from a Spanish explorer, a Catholic saint, and a bay that kept its name for more than 400 years. San Diego is not a nickname. It is a piece of California history that survived Spanish rule, Mexican rule, and American statehood.
Next time you hear the name San Diego, remember Saint Didacus of Alcalá, the explorers, and the first California mission that made the name permanent.
Sources & References
- Encyclopaedia Britannica — “San Diego”
- National Park Service — “Juan Rodriguez Cabrillo”
- Mission Basilica San Diego de Alcalá — “History of Mission San Diego de Alcalá”