Thomas H. Geismar is an American graphic designer. Geismar studied concurrently at the Rhode Island School of Design and Brown University. He received a master's degree in graphic design from Yale University, School of Art and Architecture.
In 1957, Geismar founded the firm Brownjohn, Chermayeff & Geismar (now Chermayeff & Geismar & Haviv) with Robert Brownjohn and Ivan Chermayeff. Geismar has designed more than a hundred corporate identity programs. His designs for Xerox, Chase Manhattan Bank, Best Products, Gemini Consulting, PBS, Univision, Rockefeller Center and, most notably, Mobil (1964) have received worldwide acclaim.
Geismar has also had major responsibility for many of the firm's exhibition designs and world's fair pavilions. His projects include such major tourist attractions as the Ellis Isand Immigration Museum, the Statue of Liberty Museum, the Truman Presidential Library, and the redesigned Star-Spangled Banner exhibition at the Smithsonian National Museum of American History. He has received major awards in the field, including one of the first Presidential Design Awards for helping to establish a national system of standardized transportation symbols.