Alvin Saunders Johnson, an educator, economist, editor and writer, was born on December 18, 1874 near Homer, Nebraska. He received a BA in classics from the University of Nebraska (1897), served briefly in the army during the Spanish-American War, and earned a PhD in economics from Columbia University (1902). Johnson's teaching career between 1902 and 1917 included stints at Bryn Mawr College, Columbia University, Cornell University, Stanford University, University of Nebraska, University of Texas, and University of Chicago. Throughout his teaching career, Johnson also worked as a writer and editor. At the request of New York City's Committee of Fifteen, a group of prominent citizens committed to eradicating vice in the city, Johnson participated in a study of prostitution that was published in 1902 as, The Social Evil With Special Reference to Conditions Existing in the City of New York. From 1902-1906, Johnson edited the Political Science Quarterly and from 1917 until around 1923 he was economics editor for the New Republic. In 1919, Johnson joined a group of New Republic colleagues and Columbia professors, including Charles Beard, James Harvey Robinson, John Dewey, and Wesley Mitchell, to found the New School for Social Research. Johnson served as a trustee at the school until 1922, when he was appointed director (later, president), a position he held until 1946.

From its founding, the social sciences were considered essential to the school's central purpose, and under Johnson's leadership the New School grew into an important and influential center for adult education. According to the first course catalog, the New School was devoted to a concept of lifelong learning, striving "to meet the needs of intelligent men and women interested in the grave social, political, economic and educational problems of the day." Its commitment to adult education and focus on contemporary issues remained central to the identity of the school for decades.

By 1930, the New Schoolhad outgrown its original home in the Chelsea neighborhood of New York City. Johnson turned his energy and fund raising prowess toward acquiring a new home for the New School at 66 West Twelfth Street. Designed by architect and theatrical designer Joseph Urban, the building gave Johnson an opportunity to embody the school's educational vision in physical form, creating an environment that he hoped would accomodate free inquiry and egalitarian learning while serving the needs of a busy adult student population. Johnson also invited two emerging artists, José Clemente Orozco (1883-1949) and Thomas Hart Benton (1889-1975), to create murals for the new building. A third mural by Camilo Egas (1889-1962) was added in 1932. The importance placed on art in the new building signaled Johnson's growing recognition of the role art should play in developing students' understanding of society. Indeed, by 1931, the curriculum fully reflected this expanding vision, now offering a wide range of courses in modern art, music, literature, dance, and theater in addition to economics, history, and politics. Courses in cinema, urban housing and the emerging field of psychoanalysis furthered the school's reputation as a forward-thinking institution.

In the early 1930s, in addition to leading the New School, Johnson served as associate editor, with Edwin R. A. Seligman, on The Encyclopaedia of the Social Sciences. It was in the course of his work with European contributors to the encylopaedia that he became alarmed by the rise of fascism. Johnson now trained his organizational energies on a new project, to establish a center at the New School that would enable selected scholars whose lives and careers were being upended in Europe to obtain visas to come teach in the United States. The University in Exile was born (soon known officially as the Graduate Faculty of Political and Social Science). Soon after the University in Exile got underway, Johnson launched the journal, Social Research, largely intended as an outlet for disseminating the work of the newly transplanted scholars. A second emergency effort in 1940 brought another group of scholars to the New School. Johnson also created a framework that enabled the New School to host the École Libre des Hautes Études, providing a haven for endangered French and Belgian scholars during World War II. Johnson also played a key role in efforts to secure university positions across the United States for more than a hundred threatened scholars.

In addition to his New School duties, from 1927 to 1947 Johnson served as a member of the editorial council of the Yale Review and was Professor of Economics and Director of General Studies at the Graduate School of Yale during the 1938-1939 academic year. In 1943, Johnson served as vice-chairman of New York State's Commission on Discrimination in Employment, helping to draft and pass the landmark New York Fair Employment Act of 1945, making New York the first state in the nation to prohibit discrimination in employment on the basis of race, creed, color, or national origin. The act would serve as a model for such legislation in other states.

After retiring as president in 1946, Johnson continued in his role of booster, fund raiser and guiding spirit at the New School for another twenty-five years. His annual birthday celebrations combined outpourings of affection with seminars and meetings on pressing social issues, while also serving as launch-pads for new capital campaigns and scholarships. A prolific writer throughout his life, Johnson wrote close to a thousand articles, a memoir, Pioneer's Progress, short stories, and two novels, The Professor and the Petticoat and Spring Storm.

Johnson fathered seven children with his wife Edith Henry Johnson (died 1961). The children adopted the surname Deyrup, a version of Johnson's Danish forebearers. Edith, who had earned a doctorate in philosophy from Columbia University, home-schooled the children at their home in Nyack, New York (the family divided its time between Nyack and a Manhattan apartment). Each of Johnson's children with Edith earned bachelors and advanced degrees from Barnard College or Columbia University, and all of them went on to lead distinguished careers as scholars and artists: Dorothy (1908[?]-1961), as a professional painter; Alden (1909-1999), a research chemist; Thorald (1913[?]-1984[?]) a lawyer; Natalie (1914-2007), a physician; Felicia (1917-2003), a professor of economics at The New School; Ingrith (1919-2004), chair of the Zoology Department at Barnard; and Astrith (1923-2010), a musician, artist and textile designer who taught batik at the New School. Johnson also fathered a daughter with education writer and scholar, Agnes de Lima, who served for two decades as publicity director at the New School. Their daughter, Sigrid de Lima (1921-1999), attended editor Hiram Haydn's creative writing workshop at the New School and went on to publish several novels. She was awarded the Prix de Rome in 1953.

Alvin Johnson died in June 1971.