Joanne Leonhardt Cassullo was born in Oyster Bay, New York, and raised in Texas. After her graduation from Fort Worth Country Day School, she entered Roanoke College where she majored in English, Elementary Education and Fine Arts. It was an American art history class at Roanoke that Cassullo said "awakened in me a lifelong passion for art and art history that continues to inform who I am today." Cassullo received her Bachelor of Liberal Arts degree from Roanoke and her teaching certificate from the State of Virginia in 1978. She continued her education at Southern Methodist University in Dallas, Texas, completing course work for a master's of fine arts degree in 1983.
In 1983, Cassullo was awarded a Helena Rubinstein Fellowship in Museum Studies at the Whitney Museum of American Art in New York. This prestigious Independent Study Program was for one year, during which time she was co-curator for two exhibitions in branch museums. After her experience at the Whitney, Cassullo served as a gallery assistant at the Washburn Gallery in New York. In 1985, she became the youngest member ever elected to the Whitney's board of trustees, a position that she holds today. She has served on nearly all the committees of the Whitney and currently serves as secretary, chairs the education committee and sits on all acquisition committees.
Cassullo has juried art shows including the Victory Arts Juried Competition in Dallas, Texas, and in 2007 served on The Art of Collecting panel at the Marianne Boesky Gallery in New York. She is a freelance writer, and her articles have been featured in a variety of periodicals including Harvard Business Review, Artspace, and Countryside. In addition, she has served as a special editorial consultant and prop stylist for numerous books and magazines that focus on the decorative arts.
Cassullo is founder, president and director of the Dorothea L. Leonhardt Foundation, Inc., a private philanthropic foundation named in honor of her mother who was her role model. For her support of Roanoke College, Dorothea Leonhardt was conferred an honorary Doctor of Fine Arts degree posthumously in May 1985.
For her many philanthropic activities, Cassullo was awarded the Aperture Foundation Award for Philanthropy in 2007. In addition to serving on the board of the Whitney, she serves on the boards of Creative Time, HELP USA Inc. (Housing Enterprises for the Less Privileged), and the New York City Police Foundation. She is also a council member of Rockefeller University in New York City. She has served on the boards of Friends Academy in Locust Valley, New York; the Phoenix House, Inc. in New York; the Brooklyn Academy of Music; the Children's Advocacy Center of Manhattan; and RxArt, Inc.
Cassullo is a member of the Roanoke College board of trustees, a Lifetime Distinguished Associate and is an active member of the alumni association. She is a past member of the President's Advisory Board. In 2001, Cassullo established the Joanne Leonhardt Cassullo Endowed Scholarship at Roanoke, and in 2004, Cassullo established a new professorship in art history. In addition, she has been responsible for bringing numerous visiting artists and artwork to campus. By demonstrating her dedication to her alma mater through these many generous acts, Cassullo ensures that Roanoke's students will continue to benefit from her love of art and art history.
Joanne Leonhardt Cassullo received the Roanoke College Medal in 2008.