Hillhouse was born on March 1, 1955, in Greenville, South Carolina. He attended the University of South Carolina in 1976 and received his Ph.D. from Indiana University Bloomington in 1980. He then became a postdoctoral research associate at California Institute of Technology, before taking a position in the department of chemistry at the University of Chicago in 1983.
He died from cancer at his home in Chicago on March 6, 2014, aged 59.