Preheat oven to 400°F (200°C).

Lightly drizzle tilapia filets with olive oil.

Season the filets with cajun seasoning, onion powder, garlic powder, cayenne pepper, minced thyme, ground white pepper, sea salt, and citrus zest.

Slice grapefruit, orange, and lemons into medium-thin slices.

Lay half of the citrus slices across the bottom of a baking sheet.

Place the seasoned tilapia filets on top of the citrus slices.

Cover the filets with the remaining citrus slices.

Bake for approximately 8 minutes, or until the internal temperature reaches 145°F (63°C).

Garnish with reserved citrus slices and/or parsley before serving.