Preheat oven to 400 degrees F (200 degrees C).

Toss Brussels sprouts with 1 teaspoon oil, 1 teaspoon paprika, 1/4 teaspoon salt, and 1/4 teaspoon pepper in a large bowl. Spread on a baking sheet.

Roast in the preheated oven until softened, about 15 minutes. Push to 1 side of the baking sheet.

Toss kielbasa sausage with remaining 1 teaspoon oil, 1 teaspoon paprika, 1/4 teaspoon salt, and 1/4 teaspoon pepper in the bowl. Arrange cut-side down next to the Brussels sprouts on the baking sheet.

Return to the oven and roast until Brussels sprouts are slightly crispy, about 15 minutes more. Toss together before serving.