Preheat oven to 400°F (200°C) and line a rimmed baking sheet with foil or parchment for easy cleanup.
Arrange bacon slices in a single layer without overlapping; use a wire rack on top of the sheet if desired for extra crispiness.
Place the baking sheet in the cold oven, then set to 400°F to help the fat render slowly.
Check at the 15-minute mark; thinner bacon may finish sooner while thick-cut needs more time.
Bake for 15–20 minutes until the bacon turns deep golden brown and crispy around the edges.
Remove from oven and transfer bacon to a paper towel–lined plate to drain excess grease.
Let cool for 2–3 minutes; bacon will crisp up slightly more as it rests.