Pattison Lake is a lake in the U.S. state of Washington. The lake has a surface area of , and reaches a depth of . The lake was named after James Pattison, a pioneer settler.
In June 2025, toxic algae was reported at the lake, prompting Thurston County to issue a public advisory to avoid swimming there. Samples collected from the lake detected Microcystins levels above state recreation guidelines. The advisory ended on July 16 after two satisfactory samples.