Hoffleit's interest in astronomy began with the 1919 Perseid meteor shower that she saw with her mother.[3] In 1928, she graduated cum laude with a B.A. in mathematics. She then went on to work for the Harvard College Observatory, searching for variable stars.[4] In 1938, she was awarded a Ph.D. in astronomy from Radcliffe College[5] and was subsequently hired, in 1948, as an astronomer at Harvard University. She remained at Harvard until 1956 when she moved to Yale University. She remained at Yale until retirement in 1975.[6]
At Yale she followed in the footsteps of Ida Barney, taking over her astrometric work, and of whom she later wrote "To know [her] was a pleasure, inspiration, and privilege, both at work and socially."[7] Hoffleit also served as director of the Maria Mitchell Observatory on Nantucket Island from 1957 to 1978, where she ran summer programs (May–October) for more than 100 students, many of whom went on to successful careers in astronomy.[2] In her final years at Yale, Hoffleit taught basic courses in astronomy to undergraduates. Her passionate lectures in Davies Hall, usually with over 100 students, inspired and awed them.[citation needed] She engendered a lifelong interest in astronomy for young women and men, many of whom were just satisfying a prerequisite to their undergraduate degrees.