Penryn (Washo: Pénwin)[4] is a census-designated place[2] in Placer County, California, in the United States.

Back home in North Wales, Griffith, like his father before him, worked in the Penrhyn Slate Quarry.

To simplify things and avoid the inevitable misspellings that were likely to occur, on the evening of May 17, 1865, Griffith, after discussing the matter with Central Pacific legal counsel Edwin Bryant Crocker (known later for the Crocker Art Museum), agreed to drop the “h” from the original Welsh spelling and settled on the name, and spelling, we know today.

The following day, Griffith recorded this auspicious event in his diary: "Concluded last night with Judge Crocker to call this quarry Penryn."

Griffith's employees all lived in the immediate area, so there were plenty of people, but no businesses outside of what amounted to a small "company store" near the quarry.

That year, a large frame building housing a railroad depot, store and saloon, went up on the West side of the Central Pacific mainline, just South of today's English Colony Way.

By the mid-1870s Penryn was an established community with a fine new schoolhouse, a hotel, at least one blacksmith shop, two or three stores and an equal number of saloons.

Mottled in more-or-less equally sized specks of black and white, it appears a medium-to-dark gray in color, at first glance, but takes on an almost bluish-gray hue when viewed in a subdued light or, when wet or polished.

Joel Parker Whitney owned thousands of acres of land in the Penryn area in the late 19th century.

According to the United States Census Bureau, the CDP covers an area of 1.8 square miles (4.7 km2), all of it land.

Placer County Transit provides weekday commuter service to/from the Penryn Park and Ride to/from Downtown Sacramento.