In a 9x9 baking dish or reusable bag, combine all ingredients for the catfish marinade. Add the catfish fillets to the marinade and let them marinate for 20 minutes.
In a 9x13 baking dish or large container, mix together all ingredients for the catfish breading. Set aside.
In a medium bowl, combine all ingredients for the homemade tartar sauce. Adjust seasoning to taste.
In a large pot, heat 2-3 cups of frying oil until hot. Take one catfish fillet at a time, coat it thoroughly in the breading mixture, pressing gently to adhere. Shake off any excess breading and carefully place the coated fillet into the hot oil.
Fry the catfish for 3-4 minutes on each side, until golden and crispy. Ensure the internal temperature reaches 145 degrees. Transfer the fried catfish to a roasting rack to drain excess oil.
Serve the crispy fried catfish with homemade tartar sauce and extra lemon wedges on the side. Enjoy!