In a letter to employees, he said the business was “firing on all cylinders, just as the world needs us to”, as it reported a 43% rise in sales to $125.6bn (£92bn) for the Christmas quarter ending in December.
Mr Bezos said his departure as chief executive would give him more time to focus on side projects such as space exploration company Blue Origin, fighting against climate change, and overseeing The Washington Post, the newspaper he owns.
But he remains Amazon‘s biggest shareholder, and looks likely to continue to have a major influence over the company’s direction.
Chief financial officer Brian Olsavsky told reporters: “Jeff is not really going anywhere. It’s more of a restructuring of who’s doing what.”
Amazon has thrived during the coronavirus pandemic as the closure of physical retail prompted an acceleration in online consumer demand.
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In recent years it has also been buoyed by its expanding cloud data storage business and in addition has branched into sports and entertainment streaming.
Amazon’s revenues for the whole of 2020 climbed 38% to $386bn (£283bn) and profits rose 84% to $21.3bn (£15.4bn).
Mr Bezos’s stellar success since founding Amazon as an online bookseller in 1995 saw him catapulted to the status of world’s richest man last year, before being overtaken by Tesla’s Elon Musk.
He told investors on Tuesday: “If you do it right, a few years after a surprising invention, the new thing has become normal.
“People yawn. That yawn is the greatest compliment an inventor can receive. When you look at our financial results, what you’re actually seeing are the long-run cumulative results of invention.
“Right now I see Amazon at its most inventive ever, making it an optimal time for this transition.”
Mr Bezos said that new products would be among the areas he would prioritise in his new role at the company.
Russ Mould, investment director at AJ Bell, said: “The fact he is stepping down as chief executive of Amazon doesn’t mean he is disappearing; far from it as he is becoming executive chairman.
“The chairman’s role is to keep the chief executive in order, so Bezos will still be engrained in the business and be able to provide guidance on a range of strategic issues.
“He is also a major shareholder which gives him considerable influence on how the business is run.”