Nerissa Bretania Underwood (born 1954 or 1955) is a Democratic Senator in the 33rd Guam Legislature, vice chairwoman of the Democratic Party of Guam, a former superintendent of the Guam Department of Education, and the wife of former Democratic Guam Congressional Delegate Robert A. Underwood. She is currently serving as the chairperson of the legislature's Committee on Early Learning, Juvenile Justice, Public Education and First Generation Initiatives and as the vice chairperson on the Committee on Higher Education, Culture, Public Libraries, and Women's Affairs.