Preheat your smoker to 225°F and prepare the grates for direct smoking.
Choose your wood for smoking. Fruitwoods like apple or cherry work well with Cornish hens.
In a bowl, combine olive oil, garlic, paprika, salt, pepper, dried thyme, and dried rosemary to create the rub.
Pat the Cornish hens dry with paper towels.
Apply the rub mixture all over the hens, including the cavity.
Insert half a lemon and a sprig of fresh rosemary into the cavity of each hen, if using.
Place the prepared hens directly on the smoker grates, breast side up.
Close the lid and smoke for about 2 to 2.5 hours, or until the internal temperature of the thickest part of the thigh reaches 165°F.
Remove the hens from the smoker and let them rest for 10 minutes before serving. Enjoy!