Heat olive oil in a large skillet over medium-high heat. Season the diced chicken with salt, pepper, oregano, and paprika. Add chicken to the pan and cook for 5–6 minutes until golden and cooked through. Remove from skillet and set aside.
In the same pan, add a little more oil if needed. Add diced red onion and garlic, sautéing until softened and fragrant, about 2–3 minutes.
Add the orzo pasta and stir for 1–2 minutes to lightly toast. Pour in the chicken broth, scraping up any browned bits from the bottom. Bring to a boil, then reduce heat to a simmer. Cook uncovered for 8–10 minutes, stirring occasionally, until orzo is tender and most of the liquid is absorbed.
Stir in cherry tomatoes and return the cooked chicken to the skillet. Cook for another 2–3 minutes until the tomatoes soften slightly and everything is heated through.
Remove from heat and stir in lemon juice and zest. Sprinkle with olives, crumbled feta, and fresh parsley. Adjust seasoning if needed and serve warm.