David Starr Jordan (January 19, 1851 – September 19, 1931) was the founding president of Stanford University, serving from 1891 to 1913. He was an ichthyologist during his research career. Prior to serving as president of Stanford University, he served as president of Indiana University from 1885 to 1891.

Jordan was also a strong supporter of eugenics, and his published views expressed a fear of "race-degeneration", asserting that cattle and human beings are "governed by the same laws of selection". He was an antimilitarist since he believed that war killed off the best members of the gene pool, and he initially opposed American involvement in World War I.

Jordan was born in Gainesville, New York, and grew up on a farm in upstate New York. His parents made an unorthodox decision to educate him at a local girls' high school. His middle name, Starr, does not appear in early census records, and was apparently self-selected; he had begun using it by the time that he was enrolled at Cornell. He said that it was in honour of his mother's devotion to the minister Thomas Starr King but also due to his admiration for the night sky which he expressed at a young age.

He was inspired by Louis Agassiz to pursue his studies in ichthyology. In the mid-19th century Agassiz was incomparably influential and trained "nearly all" of the leading naturalists in the United States. Simultaneously, according to historian Donald Yacovone, "His revulsion for African Americans and his insistence on their inherent inferiority knew no limits. The influence of [Agassiz's] damaging ideas cannot be overestimated." Jordan was part of the first freshman class of undergraduates at Cornell University, where he graduated in 1872 with a master's degree in botany.

In his autobiography, The Days of a Man, he wrote, "During the three years which followed [my entrance as a 'belated' freshman in March 1869], I completed all the requirements for a degree of Bachelor of Science, besides about two year of advanced work in Botany. Taking this last into consideration, the faculty conferred on me at graduation in June 1872, the advanced degree of Master of Science instead of the conventional Bachelor's Degree ... it was afterward voted not to grant any second degree within a year after the Bachelor had been received. I was placed, quite innocently, in the position of being the only graduate of Cornell to merge two degrees into one." His master's thesis was on the topic "The Wild Flowers of Wyoming County".

Jordan initially taught natural history courses at several small Midwestern colleges and secondary schools, including at Indianapolis High School.

In 1875, while in Indianapolis, Jordan obtained a Doctor of Medicine degree from Indiana Medical College. The Indiana Medical College in Indianapolis opened in 1869, but merged out of existence in 1878. Standards at the college were not particularly high. Jordan himself, reflecting on the experience noted that "I was also able to spend some time in the Medical College, from which, in the spring of 1875, I received the (scarcely earned) degree of Doctor of Medicine, though it had not at all been my intention to enter that profession." The following year, in 1876, Jordan taught comparative anatomy at the college.

Jordan also holds an honorary PhD, awarded to him by Butler University in 1877.