Kaletsky was educated at Westminster City School, at that time a grammar school in the City of Westminster in central London, followed by King's College, Cambridge, where he graduated with a first class honours degree in Mathematics, and then at Harvard, where he was a Kennedy Memorial Scholar and gained a master's degree in economics.

In early 2012, Kaletsky began his new post, in the Analysis and Opinion section of the Reuters online newspaper, where he wrote a weekly column.

[4] He published the "controversial" book Capitalism 4.0: The Birth of a New Economy in the Aftermath of Crisis in 2011, putting the 2007 to 2009 recession into "historical and ideological perspective.

"[9] In Project Syndicate in February 2016, Kaletsky confidently but incorrectly predicted that Britain would not vote to leave the European Union.

[10] In March 2020, he spoke at the Investment Week Funds to Watch conference, talking about projected effects of coronavirus.

[13] Kaletsky is married to Fiona Murphy, a documentary film producer, and they have three children: Kitty, Misha, and Sasha.