Add buttermilk and milk into a bowl and whisk to combine.
Combine flour, cornmeal and seasoned salt in a pie plate.
Heat oil to 350°F in a cast iron skillet or heavy bottom pan.
Dip squash slices into milk and dredge in flour and cornmeal mixture. Shake off excess and place carefully into heated oil. Cook about 6-8 squash at a time. Cook about 3-5 minutes per side until golden brown. Remove to a paper towel lined wire rack to drain.