Heat a large skillet or Dutch oven over medium-high heat and cook the ground beef, breaking it up with a spoon, until browned and cooked through, about 5–7 minutes. Season with salt and pepper to taste. Drain any excess grease if needed. Remove and set aside.
Add the orzo to the same skillet and toast for 1–2 minutes, stirring frequently.
Pour in the water, bring to a boil, then reduce heat to low. Cover and cook for 10–12 minutes, stirring occasionally, until the orzo is tender and most of the liquid is absorbed.
Stir in the cooked beef, spinach, and Alfredo sauce. Cook for 2–3 minutes, stirring until the spinach wilts and everything is creamy and heated through. Taste and season with additional salt and pepper if needed before serving.