Wesco Financial Corporation was an American diversified financial corporation headquartered in Pasadena, California. Wesco was originally the holding company for Mutual Savings, a savings and loan association. Mutual Savings' thrift operations were sold to CenFed Bank in 1993. It was for a long time 80.1% owned by Blue Chip Stamps, which is now completely and fully owned by Berkshire Hathaway, which is controlled by legendary investor Warren Buffett. Charlie Munger, the vice-chairman of Berkshire Hathaway and Buffett's business partner, was CEO and chairman of Wesco from 1984 to 2011. Munger, formerly a practicing attorney, is known for his straight-shooting style and his conduct at the now discontinued Wesco shareholder meetings in Pasadena, where he used to interact with the outside investors at considerable length. In June 2011, Berkshire Hathaway acquired the approximately 20% of Wesco that it did not already own, making it a wholly owned subsidiary of that company.

Pasadena is a city in Los Angeles County, California, United States, 11 miles (18 km) northeast of downtown Los Angeles. It is the most populous city and the primary cultural center of the San Gabriel Valley. Old Pasadena is the city's original commercial district.