Alexei Vladimir "Alex" Filippenko is an American astrophysicist and professor of astronomy at the University of California, Berkeley. Filippenko graduated from Dos Pueblos High School in Goleta, California. He received a Bachelor of Arts in physics from the University of California, Santa Barbara in 1979 and a Ph.D. in astronomy from the California Institute of Technology in 1984, where he was a Hertz Foundation Fellow. He was a postdoctoral Miller Fellow at Berkeley from 1984 to 1986 and was appointed to Berkeley's faculty in 1986. In 1996 and 2005, he was a Miller Research Professor, and he is currently a Senior Miller Fellow. His research focuses on supernovae and active galaxies at optical, ultraviolet, and near-infrared wavelengths, as well as on black holes, gamma-ray bursts, and the expansion of the Universe.