Preheat the oven to 350 F (176 C). Line a large rimmed baking sheet with aluminum foil.
In a medium bowl, mix together the cranberries, brown sugar, orange zest, and orange juice. Let this rest while you prepare the chicken and potatoes.
To the prepared baking sheet, add the chicken thighs, baby potatoes, olive oil, garlic, and salt. Toss to coat.
Make sure the chicken is skin side up, and place it between the potatoes so it’s all in one even layer.
Sprinkle the dried rosemary evenly over the chicken and potatoes.
Sprinkle the cranberries over the baking dish, trying to fill all the nooks and crannies with them. Move them around so that everything is in one layer. I sprinkle mine over the potatoes and avoid the chicken, because if the chicken is uncovered the skin will get golden and crispy.
Bake uncovered in the preheated oven for 1 hour and 25 minutes, or until the chicken reaches an internal temperature of 165 F on an instant read meat thermometer and the skin is golden brown and crispy.