Dr. Harold Willis Dodds, 91, president of Princeton University from 1933 until retiring in 1957, died Saturday in a retirement home in Hightstown, N.J. He had pulmonary and circulatory ailments.

During his years as Princeton's president, the university established new departments in music, religion, aeronautical engineering, and Near Eastern Studies.Dr. Dodds was responsible for naming the university's School of Public and International Affairs after another Princeton president, Woodrow Wilson.

It also was during this time that the physical plant of the University doubled with the acquisition of a new science research site. While undergraduate enrollment increased about 25 percent to 2,924, the number of graduate students increased from 180 to 640.

He was a strong defender of a liberal arts college education. He said that a liberal education "teaches those habits of thought and analysis which permit students to absorb new knowledge and apply it with judgement."

A profile of Dr. Dodds which appeared in the 1957 issue of The New York Times, characterized him as shaggy and homespun and told a story dating from the 1940s. It seems that a student was struggling across campus with a new mattress for his room when a man approached from behind and offered to help. After the task was completed the student turned to thank his "helper" and found it was president Dodd's.

But the same man who could quietly help a struggling student also could speak with a firm voice. In the late 1940s, he refused a request of the house Un-American Activities Committee that he submit a list of books used in Princeton's political science courses. He called it "an intrusion by government into an area of education that ought to remain independent and not political."

He also created a stir in 1956 when he refused to overrule a student organization that had invited Alger Hiss, a former State Department official who had been convicted of perjury, to speak at the university. Dr. Dodds said that although he had warned the student group of the "implications of the invitation" he thought it unwise to overrule the students' invitation.

He began his Princeton career as a political science professor in 1927 and served as chairman of the administrative committee of the school's new school of public and international affairs from 1930 until becoming Princeton's 15th president in June 1933.

In addition to serving as Princeton's president for nearly a quarter-century, Dr. Dodds served with a number of government organizations at the state and national level. He once said that it was a duty as well as a profitable experience for educators to apply their knowledge to the practical affairs of the nation.

In 1943 he was named head of the American delegation to the Anglo-American conference on refugee problems held in Bermuda. He was a member of the President's Advisory Committee on Universal Military Training in 1947 and recommended universal training for the nation's youth.

In the mid-1950s, he was head of a task force on personnel and civil service reform of the "Hoover Commission" the Commission on Organization of the Executive Branch of the Government that was chaired by former President Herbert Hoover.

Dr. Dodds called for the creation of an elite 1,000-person corps of senior civil servants in the government and for intense recruiting efforts to enlist the brightest graduates of American universities to enter the Civil Service. t

Earlier in his career, Dr. Dodds had been an adviser to Latin American nations on election laws and also had directed a study in the 1930s on the finances and administration of the state government of New Jersey for the governor of that state.

Dr. Dodds was born in Utica, Pa. He was a 1909 graduate of Grove City College in Grove City, Pa., earned a master's degree at Princeton and a doctoral degree in political science at the University of Pennsylvania in 1917.

He taught English and Latin in high schools in Pennsylvania from 1909 to 1911, then was a member of the faculty of Purdue University, the old Western Reserve University, the University of Pennsylvania and New york University before going to Princeton to teach courses on municipal government and public administration.

In 1920 he was named secretary of the National Municipal League and editor of the League's monthly magazine, posts he held until 1933. From 1934 to 1937, he was the League's president.

Survivors include his wife of 62 years, the former Margaret Murray of Hightstown, N.J., and a brother, Dr. John Wenell Dodds of Stanford, Calif.