Heat 1 tablespoon olive oil in a large skillet over medium-high heat.
Season chicken with salt, pepper, 2 teaspoons Italian seasoning, 1/2 teaspoon garlic powder, onion powder, and lemon zest.
Add butter to the pan, then cook chicken for about 3 minutes per side until golden and cooked through (165°F internal temperature). Remove and set aside.
In the same skillet, add remaining oil and butter.
Add zucchini and squash, season with salt, remaining Italian seasoning, and garlic powder. Cook for about 4 minutes until tender.
Return chicken to the skillet and drizzle with lemon juice. Toss to combine.
Sprinkle Parmesan cheese and parsley over the top.
Serve warm and enjoy your Skillet Lemon Parmesan Chicken.