Thaler was born in East Orange, New Jersey. His mother, Roslyn (Melnikoff, 1921–2008), was a Teacher, and later a real estate agent while his father, Alan Maurice Thaler (1917–2004), was an actuary at the Prudential Financial in Newark, New Jersey, and was born in Toronto. He grew up with two younger brothers. His great-great grandfather, Selig Thaler (1831–1903) was from Berezhany, Ukraine. He is married to France Leclerc, a former marketing professor at the University of Chicago and avid Photographer. He has three children from his first marriage.

He graduated from Newark Academy, before going on to receive his Bachelor of Arts in 1967 from Case Western Reserve University, and his master's in 1970 and doctorate in 1974 from the University of Rochester, writing his thesis on "The Value of Saving A Life: A Market Estimate" under the supervision of Sherwin Rosen.

Between 1977 and 1978, Thaler spent a year at Stanford University collaborating and researching with Daniel Kahneman and Amos Tversky, who provided him with the theoretical framework to fit many of the economic anomalies that he had identified, such as the "endowment effect".

From 1978 to 1995, he was a faculty member at the SC Johnson College of Business at Cornell University .

Thaler gained some attention in the field of mainstream economics for publishing a regular column in the Journal of Economic Perspectives from 1987 to 1990 titled Anomalies, in which he documented individual instances of economic behavior that seemed to violate traditional microeconomic theory.

Since 1991, Thaler is also the co-director of the National Bureau of Economic Research Behavioral Economics Project.

Thaler also is the founder of an asset management firm, Fuller & Thaler Asset Management, which believes that Investors will capitalize on cognitive biases such as the endowment effect, loss aversion and status quo bias. Since 1999, he has been the Principal of the said firm, which he co-founded in 1993. Russell Fuller, in charge of the firm's daily operations, said Thaler has changed the economics profession in that: "He doesn't write papers that are full of math. He writes papers that are full of Common sense."

Paul Krugman, the 2008 winner of the Nobel Memorial Prize in Economics, tweeted "Yes! Behavorial econ is the best thing to happen to the field in generations, and Thaler showed the way." However, Thaler's selection was not met with universal acclaim; Robert Shiller (one of the 2013 laureates) noted that some economists still view Thaler's incorporation of a psychological perspective within an economics framework as a dubious proposition. And, an article in The Economist simultaneously praised Thaler and his fellow behavioral colleagues while bemoaning the practical difficulties that have resulted from causing "economists as a whole to back away a bit from grand theorising, and to focus more on empirical work and specific policy questions."

Thaler has written a number of books intended for a lay reader on the subject of behavioral economics, including Quasi-rational Economics and The Winner's Curse, the latter of which contains many of his Anomalies columns revised and adapted for a popular audience. One of his recurring themes is that market-based approaches are incomplete: he is quoted as saying, "conventional economics assumes that people are highly-rational—super-rational—and unemotional. They can calculate like a computer and have no self-control problems."

Thaler made a cameo appearance as himself in the 2015 movie The Big Short, which was about the credit and housing bubble collapse that led to the 2008 global financial crisis. During one of the film's expository scenes he helped pop star Selena Gomez explain the 'hot hand fallacy,' in which people think that whatever is happening now will continue to happen into the Future.

Immediately following the announcement of the 2017 prize, Professor Peter Gärdenfors, Member of the Economic Sciences Prize Committee, said in an interview that Thaler had "made economics more human".