Whisk together olive oil, lemon juice, garlic, oregano, paprika, salt, and pepper. Coat the chicken evenly and marinate for at least 30 minutes, or up to 8 hours for deeper flavor.
Heat a skillet or grill pan over medium-high heat. Cook the chicken 5–7 minutes per side until fully cooked through. Rest for 5 minutes, then slice.
Dice the cucumber, halve the cherry tomatoes, thinly slice the red onion, and prepare the olives.
Stir together the Greek yogurt, grated cucumber, garlic, lemon juice, dill, and salt until smooth. Refrigerate until ready to serve.
Divide the rice between bowls. Top with sliced chicken, tomatoes, cucumber, onion, olives, and feta. Add a generous scoop of tzatziki and garnish with fresh herbs.
Serve immediately with lemon wedges on the side. Enjoy warm or chilled.