Judith Giuliani (born Judi Ann Stish on December 16, 1954, in Hazleton, Pennsylvania) is an American registered nurse and former medical sales executive. She began her career in nursing and later transitioned into pharmaceutical sales and medical fundraising, working for organizations including the American Red Cross. She married census bureau director John Nathan in 1984 (becoming Judi Nathan) and divorced in 2000. She met Rudy Giuliani in 1999 while working as a fundraiser and married him on May 24, 2003, becoming his third wife. During Rudy Giuliani's tenure as U.S. Attorney and Mayor of New York City, she was involved in his public life, though their relationship faced scrutiny due to his previous family dynamics.

Post-mayoralty, she became active in philanthropy and business consulting, serving as a managing director at the philanthropic consulting firm Changing Our World, where she advised nonprofits on fundraising strategies. She was a founding board member of the Twin Towers Fund, established to support victims of the 9/11 attacks. The Giulianis were involved in various business ventures together, including Rudy's consulting firm. Their marriage deteriorated amid personal and financial strains, leading to separation in 2014 and divorce finalization on December 11, 2019, with media reports citing disputes over assets and Rudy's presidential ambitions.

Throughout her life, she has been noted for her Midwestern roots after attending college in Missouri, and her career reflects a blend of healthcare, sales, and charitable work. She has no prominent political role but was peripherally connected to Republican networks through her marriage. Allegations during the divorce included claims of financial mismanagement and infidelity, though no criminal charges resulted. Since the divorce, she has largely maintained a low profile, focusing on her professional background in nursing and philanthropy.