Sir Michael Jonathan Moritz KBE (born 12 September 1954) is a Welsh billionaire venture capitalist, philanthropist, author, and former journalist. Moritz works for Sequoia Capital, wrote the first history of Apple Inc., The Little Kingdom, and authored Going for Broke: Lee Iacocca's Battle to Save Chrysler. Previously, Moritz was a staff writer at Time magazine and a member of the board of directors of Google. He studied at the University of Oxford and the Wharton School of the University of Pennsylvania and went on to found Technologic Partners before becoming a venture capitalist in the 1980s. Moritz was named as the No. 1 venture capitalist on the Forbes Midas List in 2006 and 2007.

Michael Jonathan Moritz was born to a Jewish family in Cardiff, Wales, on 12 September 1954. His father, Ludwig Alfred Moritz (1921–2003), was a Jew who fled Nazi Germany. A professor of Classics at Cardiff University, in the 1970s, he became its Vice Principal (Administration). His mother, Doris (née Rath; 1924–2019), also fled Nazi Germany. Moritz attended Howardian High School in Cardiff.

Moritz earned a bachelor's degree in history at Christ Church, Oxford and, in 1978, an MBA from the Wharton School of the University of Pennsylvania as a Thouron scholar.

Moritz first worked for many years as a journalist. In the early 1980s, when he was a reporter for Time, Steve Jobs contracted him to document the development of the Mac for a book he was writing about Apple. According to Andy Hertzfeld, in response to the fact that a history of another computer company had been published a year earlier, Jobs said: "Mike's going to be our historian." As he was close in age to many on the development team, he seemed to be a good choice.

By late 1982, Moritz was Time's San Francisco Bureau Chief and working on the special Time Person of the Year issue, which, according to Jobs, was initially supposed to be about him. His research included a lengthy interview with Jobs' high school girlfriend, Chrisann Brennan, in which she discussed the history of their child, Lisa. Moritz's follow-up interview with Jobs on the subject led to denial of paternity on his part. The issue also contained negative commentary on Jobs from other Apple employees. The special issue was renamed Machine of the Year prior to publication, celebrated The Computer and declared that "it would have been possible to single out as Man of the Year one of the engineers or entrepreneurs who masterminded this technological revolution, but no one person has clearly dominated those turbulent events. More important, such a selection would obscure the main point. TIME's Man of the Year for 1982, the greatest influence for good or evil, is not a man at all. It is a machine: the computer." Jobs cut off all ties with Moritz after the issue was published and threatened to fire anyone who communicated with him. According to Hertzfeld, "some of us talked with Mike again surreptitiously, as he was putting the finishing touches on his book around the time of the Mac introduction" and the resulting text, The Little Kingdom: the Private Story of Apple Computer, "remains one of the best books about Apple Computer ever written".

In 2009, 25 years after The Little Kingdom, Moritz published a revised and expanded follow-up: Return to the Little Kingdom: How Apple and Steve Jobs Changed the World. In the prologue to Return to the Little Kingdom, Moritz states that he was as incensed as Jobs was about the Time Magazine special issue:

Steve rightly took umbrage over his portrayal and what he saw as a grotesque betrayal of confidences, while I was equally distraught by the way in which material I had arduously gathered for a book about Apple was siphoned, filtered, and poisoned with a gossipy benzene by an editor in New York whose regular task was to chronicle the wayward world of rock-and-roll music. Steve made no secret of his anger and left a torrent of messages on the answering machine I kept in my converted earthquake cottage at the foot of San Francisco's Potrero Hill. He, understandably, banished me from Apple and forbade anyone in his orbit to talk to me. The experience made me decide that I would never again work anywhere I could not exert a large amount of control over my own destiny or where I would be paid by the word. I finished my leave [and] published my book, The Little Kingdom: The Private Story of Apple Computer, which I felt, unlike the unfortunate magazine article, presented a balanced portrait of the young Steve Jobs.

In 1986, Moritz joined Sequoia Capital after co-authoring Going for Broke: The Chrysler Story with Barrett Seaman, Time's Detroit bureau chief. After leaving Time, Moritz co-founded Technologic Partners, a technology newsletter and conference company.