The California hide trade was a trading system of various products based in cities along the California coastline, operating from the early 1820s to the mid-1840s.

In exchange for hides and tallow from cattle owned by California ranchers, sailors from around the globe, often representing corporations, swapped finished goods of all kinds. The trade was the essential constituent of the region’s economy at the time, and encompassed cities extending from Canton to Lima to Boston, and involved many nations including Russia, Mexico, the United States, and the United Kingdom.

Sailing ships purchased each hide for one American dollar, to sell for a profit at a distant port. Such hides were sold for three dollars in Boston where shoemakers finished the leather.

The California hide trade was based on the export of hide, horns and tallow during the early nineteenth century from around 1810. Rancheros (affluent cattle farmers) and their vaqueros (cowboys) cared for free-ranging livestock along the California seaboard with the help of a Native American workforce. The cattle were not only the source of their food and many common supplies, but also their economy and livelihood. The hides of the cattle were taken to the shore and fat from the cattle was liquefied and separated into tallow, collected in repositories crafted from hides known as botas. Both goods would be stockpiled near hub ports like San Diego and Monterey to await sale to international trading vessels.

Constituting the most widely traded good, the California hides were often known as “California banknotes” due to their common use as a medium of exchange. Richard Henry Dana wrote that sailors called the hides "California dollars". They would first need to be cured, cleaned, stretched, dried in the summer sun, whipped, salted, and folded, a long and tedious process completed by sailors themselves with the aid of Native Americans and the Hawaiian Kanaka peoples, together called “droghers”. Then they would be taken onto boats and rowed out to the ships, bound for Boston and the Northeast, where they would be crafted for use into leather-based goods like shoes and boots. The tallow, on the other hand, was shipped to South American countries such as Peru and Chile and used to make candles and soap.

In order to take part in the exchange itself, the Mexican government, which ruled California at this time, instituted a fee for foreign ships to pay upon entry into the coastal waters, a fee often manipulated and avoided by trading captains through subterfuge and bribery of collectors. A tariff system charging up to 15,000 pesos enacted by the Mexican government would be paid at the customs house at Monterey, which allowed trading vessels to buy and sell goods at all of the California ports. To be able to evade the tariff was considered the mark of a professional and a badge of honor by many captains of the day. Predominantly American vessels, which negotiated high tariffs on their payloads via honest or dishonest means, often saw returns three times the value of the cargo which they brought.

The settlers (Spanish speakers born in the area became known as Californios) were able to purchase any number of manufactured products from trading ships – notably described by the writer Richard Henry Dana as “floating department stores”. Products purchased by the Californios and others were diverse and significant, many being finished goods not fabricated in the region, including silk, wine, sugar, lace, cotton, hats, horses, clothes, tobacco, cutlery and tea from abroad.

By the mid-1820s, the hide and tallow trade, facilitated by Spanish missions and their clergy and later replaced by private ranches, represented the key profitable industry in California, taxes on their primary products propping up the regional economy and infrastructure. California ports such as San Diego, Santa Cruz, Santa Barbara, San Luis Obispo, San Pedro and Monterey would grow to prominence and success in California as instrumental ports of commerce.