The average asking price for a used 2018 Cadillac CT6 is $23,410, with 83,437 miles on average, across 117 cars for sale at U.S. dealers as of Nov 10, 2026.
Used and certified cars for sale at US dealers, each car counted once. Days listed are the dealer’s own days on market where they publish it. Price moves compare the same cars at both ends of the window.