The company was created as a result of what Jeff Bezos called his "regret minimization framework" – to avoid regretting, in his old age, not having tried to participate in the emerging internet with his own startup. In 1994, Bezos left his job as a vice president at D. E. Shaw & Co., a Wall Street firm, and moved to Seattle, Washington, where he began to work on a business plan for what would become Amazon.com.

On July 5, 1994, Bezos initially incorporated the company in Washington state with the name Cadabra, Inc. After a few months, he changed the name to Amazon.com, Inc, because a lawyer misheard its original name as "cadaver". Bezos selected this name by looking through a dictionary; he settled on "Amazon" because it was a place that was "exotic and different", just as he had envisioned for his Internet enterprise. The Amazon River, he noted, was the biggest river in the world, and he planned to make his store the biggest bookstore in the world. Additionally, a name that began with "A" was preferred because it would probably be at the top of an alphabetized list. Bezos placed a premium on his head start in building a brand and told a reporter, "There's nothing about our model that can't be copied over time. But you know, McDonald's got copied. And it's still built a huge, multibillion-dollar company. A lot of it comes down to the brand name. Brand names are more important online than they are in the physical world."

In its early days, the company was operated out of the garage of Bezos's house on Northeast 28th Street in Bellevue, Washington.

After reading a report about the future of the Internet that projected annual web commerce growth at 2,300%, Bezos created a list of 20 products that could be marketed online. He narrowed the list to what he felt were the five most promising products, which included: compact discs, computer hardware, computer software, videos, and books. Bezos finally decided that his new business would sell books online, because of the large worldwide demand for literature, the low unit price for books, and the huge number of titles available in print. Amazon was founded in the garage of Bezos' rented home in Bellevue. Bezos' parents invested almost $246,000 in the start-up.

On July 16, 1995, Amazon opened as an online bookseller, selling the world's largest collection of books to anyone with World Wide Web access. The first book sold on Amazon.com was Douglas Hofstadter's Fluid Concepts and Creative Analogies: Computer Models of the Fundamental Mechanisms of Thought. In the first two months of business, Amazon sold to all 50 states and over 45 countries. Within two months, Amazon's sales were up to $20,000 per week. In October 1995, the company announced itself to the public. In 1996, it was reincorporated in Delaware. Amazon issued its initial public offering of capital stock on May 15, 1997, at $18 per share, on the NASDAQ stock exchange under the symbol AMZN.

Barnes & Noble sued Amazon on May 12, 1997, alleging that Amazon's claim to be "the world's largest bookstore" was false because it "...wasn't a bookstore at all. It's a book broker." The suit was later settled out of court and Amazon continued to make the same claim. Walmart sued Amazon on October 16, 1998, alleging that Amazon had stolen Walmart's trade secrets by hiring former Walmart executives. Although this suit was also settled out of court, it caused Amazon to implement internal restrictions and the reassignment of the former Walmart executives.

In 1999, Amazon first attempted to enter the publishing business by buying a defunct imprint, "Weathervane", and publishing some books "selected with no apparent thought", according to The New Yorker. The imprint quickly vanished again, and as of 2014 Amazon representatives said that they had never heard of it. Also in 1999, Time magazine named Bezos the Person of the Year when it recognized the company's success in popularizing online shopping.

On January 22, 2018, Amazon Go, a store that uses cameras and sensors to detect items that a shopper grabs off shelves and automatically charges a shopper's Amazon account, was opened to the general public in Seattle. Customers scan their Amazon Go app as they enter, and are required to have an Amazon Go app installed on their smartphone and a linked Amazon account to be able to enter. The technology is meant to eliminate the need for checkout lines. Amazon Go was initially opened for Amazon employees in December 2016. By the end of 2018, Amazon was operating a total of 8 Amazon Go stores located in Seattle, Chicago, San Francisco and New York. As of August 2024, Amazon Go had 23 locations in New York, California, Washington, and Illinois.