Penn Valley is a census-designated place (CDP) in Nevada County, California.

The large Lake Wildwood master-planned community, although a separate CDP, has a Penn Valley postal address, and is sometimes considered part of the general Penn Valley community.

The community may be named for Madame Penn, the original owner of the town site.

[5] According to the United States Census Bureau, the CDP has a total area of 2.1 square miles (5.4 km2), all of it land.

There were 666 housing units at an average density of 313.9 per square mile (121.2/km2), of which 485 (77.2%) were owner-occupied, and 143 (22.8%) were occupied by renters.

[9] Federally, Penn Valley is in California's 1st congressional district, represented by Republican Doug LaMalfa.

George Alan Smith, a local cowboy and heavy equipment operator, came up with the idea of holding a rodeo.

George enlisted the help of friends and relatives on weekends, evenings, and holidays to set posts, build fence and chutes, and put up bleachers.

The local Fire Department and residents volunteered their time and efforts to help put on the annual event.

The Penn Valley Rodeo quickly became "the summer event" for people from all over California to attend.