Begley was born Ludwik Begleiter in Stryi, then part of the Polish Republic and now in Ukraine, the only child of a physician.

After graduating from Erasmus Hall High School, Begley studied English literature at Harvard College (AB '54, summa cum laude), where he worked at The Advocate, an undergraduate literary magazine.

In March 1974, Begley married his present wife, Anka Muhlstein, a historian and biographer born in Paris.

Upon his return to New York, Begley headed the firm’s international practice for many years, his work being concentrated on large projects in Australia, Algeria, Latin America, Canada and Europe, for Japanese, European and Brazilian as well as American clients.

Begley's first novel, Wartime Lies, was based on his childhood as a Polish Jew who escaped the Nazi death camps.

Payne made many changes from the book, though Begley commented in an essay in The New York Times that "my most important themes were treated with great intelligence and sensitivity" and felt the movie was "a gem of original filmmaking.

In 2001, a selection of Begley's essays and journalistic pieces was published by Suhrkamp Verlag (Frankfurt) under the title Das Gelobte Land.

Venedig Unter Vier Augen, a book on Venetian themes by Anka Muhlstein and Louis Begley, was published in 2003 by Marebuch Verlag (Hamburg).