Tennessee confirmed the signing Friday.
The 5-foot-8 guard led Western Michigan in scoring last season, and Walker will have two seasons of eligibility after graduating in three years with a political science degree.
"Jordan brings experience at the guard position and provides us much-needed depth on the perimeter," Harper said. "She is a terrific addition to the rest of our roster, as she can knock down the open shot, create off the bounce and distribute the ball. I was impressed with her level of maturity, and I am excited for her to be a part of our family."
Walker averaged 16 points, 6.2 rebounds, 2.5 assists and 2.1 steals per game last season. She has started 54 of 64 games in her career, scoring in double figures 38 times.
Harper also signed Keyen Green as a graduate transfer in April. Walker is the fourth graduate transfer in Lady Vols' history.