Preheat the grill to medium-high heat (about 400°F or 200°C).
Pat the chicken breasts dry with paper towels.
In a small bowl, combine the kosher salt, black pepper, garlic powder, paprika, and dried oregano.
Brush both sides of each chicken breast with olive oil.
Sprinkle the seasoning mixture evenly over both sides of each chicken breast, pressing gently to adhere.
Place the chicken breasts on the preheated grill.
Grill the chicken for 6 minutes on the first side without moving it.
Flip the chicken breasts and grill for an additional 6 minutes on the other side, or until the internal temperature reaches 165°F (74°C).
Remove the chicken from the grill and let it rest for 5 minutes before slicing and serving.