Season the chicken breasts evenly with salt and black pepper on both sides.
Heat olive oil in a large skillet over medium-high heat until shimmering.
Add the chicken breasts to the skillet and cook for 5-6 minutes on each side until golden brown and cooked through. Remove the chicken from the skillet and set aside.
Reduce the heat to medium and add the minced garlic to the skillet. Sauté for 1 minute until fragrant.
Pour in the chicken broth, scraping the bottom of the skillet to loosen any browned bits.
Add the heavy cream, lemon zest, lemon juice, orange zest, orange juice, and chopped rosemary to the skillet. Stir to combine and bring the sauce to a gentle simmer.
Cook the sauce for 3-4 minutes until it slightly thickens.
Stir in the unsalted butter until melted and the sauce is smooth.
Return the chicken breasts to the skillet, spooning the sauce over them.
Simmer for an additional 2-3 minutes to heat the chicken through and allow the flavors to meld.
Serve the creamy citrus chicken hot, spooning extra sauce over each portion.