Leonard Lauder is the chairman emeritus of The Estée Lauder Companies Inc. He was chief executive officer until 1999. Today, Estée Lauder operates several brands in the cosmetic industry, including Estée Lauder, Clinique, MAC Cosmetics, Aveda, Bobbi Brown, Smashbox and La Mer.

Lauder has long been a major benefactor of the Whitney Museum of American Art. In 1971, he joined the museum's acquisitions board and in 1977, by then president of his family's business, he became a Whitney trustee. He became president in 1990 and has been chairman since 1994. He has donated both money and many works of art to the Whitney, and is the museum's most prolific fundraiser. His 2008 donation to it of $131 million is the largest in the museum's history. Through the Leonard and Evelyn Lauder Fund, he and his wife have also sponsored several exhibitions at the Whitney. The fifth-floor permanent collection galleries are named for the couple. In 1998, he told a reporter for The New York Times that his "dream job" was to be the Whitney Museum's director. Most recently, Lauder gave $131 million for the Whitney's endowment.