Preheat the oven to 400 degrees F (200 degrees C). Line a baking sheet with parchment paper.

Toss Brussels sprouts in a bowl with olive oil, thyme, salt, and black pepper. Transfer to the prepared baking sheet in an even layer.

Cook in the preheated oven for 10 minutes; stir in cranberries. Continue cooking for 10 minutes more.

Transfer sprouts and cranberries to a serving bowl; drizzle with maple syrup and toss to coat.