Preheat the oven to 220C/440F. Line a large baking sheet with parchment paper and set aside.
Combine olive oil and lemon juice in a bowl and place the calamari in it to marinate for at least 5 minutes or up to 30 minutes.
Mix panko bread crumbs, salt, oregano, and black pepper in a bowl. Dredge the calamari in the mixture to coat it evenly.
Place the calamari on the lined tray and bake for 25 minutes until they turn golden brown.
Serve immediately.
Notes