Astoria: Or, Enterprise Beyond the Rocky Mountains is a book published in 1836 by Washington Irving.

The book describes an expedition to the mouth of the Columbia River and the ultimate failure of attempts in the early 19th century to establish a permanent American-controlled commercial base at Astoria. The 1810–1813 expedition was financed by the New York business man, John Jacob Astor, with a view to establishing a trading post for his Pacific Fur Company, in competition with British and, to a lesser extent, Russian interests in the region. As described in Astoria, the expedition involved a sea journey by the ship, Tonquin, as well as overland journeys that blazed what would ultimately become the Oregon Trail.

The War of 1812 broke out during the attempts to make the outpost at Astoria viable. Because of direct military threats from the British, along with other problems described in the book (conflicts with indigenous peoples, managerial shortcomings and the difficulties of communication across such long distances), the project ultimately failed. All of its assets were sold to the rival North West Company in 1813. As Irving documents, the expeditions took a heavy toll, with some 60 men losing their lives on land or at sea.

In 1834, John Jacob Astor commissioned Washington Irving – at that time one of the best-known American authors – to write the book as an official history of his company's Astor Expedition to Oregon. The proposal was a continuation of a long-standing relationship between the two men that lasted until Astor's death in 1848.

Irving accepted Astor's offer, but insisted on maintaining editorial control over the book's contents. In a letter to his nephew, Irving described his vision for Astoria as "not merely a history of his [Astor's] great colonial and commercial enterprise, and of the fortunes of his colony, but a body of information concerning the whole region beyond the Rocky Mountains, on the borders of the Columbia River, comprising the adventures, by sea and land, of traders, trappers, Indian warriors, hunters, etc their habits, characters, persons, costumes, etc; description of natural scenery, animals, plants etc. etc. ..."

Irving relied on a variety of sources as background for the book. Astor had organised his papers on the Astoria expeditions and settlement and made them available to Irving. Irving also employed his nephew, Pierre Munro Irving, for 2 years to do extensive background research. Other sources used were from the United States Superintendent of Indian Trade during the 1820s, the Lewis and Clark journals as well as the journals of traders Ross Cox and Gabriel Franchère and of the explorer Steven Long.

Irving took only a few months to complete the book, once all the material had been gathered and organized. Astor hosted Irving and his nephew for several months at his country estate in Hellgate, New York. In a letter to his brother, Irving attributed his rapid completion of the book to this ideal setting: "I cannot tell you how sweet and delightful I have found this retreat; pure air, agreeable scenery, a spacious house, profound quiet, and perfect command of my time and self. The consequence is that I have written more since I have been here than I have ever done in the same space of time".

Irving completed Astoria in late 1835. The book was published in October 1836 by Bentley in London and by Carey and Lea in Philadelphia. In the absence of international copyright protections, one purpose of the simultaneous publication in England and the United States was to establish copyright in the two markets.