Wallace Leslie William Sargent (February 15, 1935 – October 29, 2012) was a British-born American astronomer. He was often known as Wal Sargent. Although he became a U.S. citizen, he was born in Elsham, England. He received his Ph.D. in 1959 from Manchester University before coming to work at California Institute of Technology (Caltech) where he worked ever after, excepting an absence of four years during which he claims to have had to go back to England to find himself a wife, Anneila Sargent.
Sargent was known for his studies of quasar absorption lines. He was the Ira S. Bowen Professor of Astronomy at Caltech. He was elected a Fellow of the Royal Society in 1981.
He supervised the theses of a number of students while at Caltech, including John Huchra, Edwin Turner, Charles C. Steidel, and Alex Filippenko.
He was married to fellow Caltech astronomer Anneila Sargent from 1964 until his death.