Preheat oven to 425°F and line a large sheet pan with parchment paper.
Pat pork medallions completely dry with paper towels and place on one side of the sheet pan.
In a large bowl, toss Brussels sprouts and sweet potatoes with 2 tablespoons olive oil, then spread on the other side of the pan.
Brush pork with remaining 1 tablespoon olive oil and season everything with garlic powder, smoked paprika, thyme, salt, and pepper.
Roast for 20-25 minutes, flipping pork once halfway through, until pork reaches 145°F internal temperature and vegetables are tender and caramelized.
Let pork rest for 5 minutes before serving alongside the roasted vegetables.