In a small bowl, combine the ranch seasoning mix, garlic powder, onion powder, paprika, black pepper, and salt.
Rub the olive oil over each chicken thigh. Sprinkle the seasoning mixture evenly over both sides of the chicken thighs.
Place the chicken thighs skin-side up on a baking sheet lined with parchment paper. Bake for 35-40 minutes or until the internal temperature reaches 165°F (74°C).
If desired, drizzle with lemon juice for added zest just before serving.
Once done, remove the chicken from the oven and let it rest for a few minutes. Garnish with chopped fresh parsley.