Where is an oil filter located on a 2001 cadillac deville?

The oil filter on a 2001 Cadillac DeVille (assuming the Northstar engine) is located on the bottom of the engine, near the front. It's usually fairly accessible, but you might need to use a wrench or filter cap to remove it. It's a spin-on type filter. You'll need to look underneath the vehicle to locate it precisely. Be aware of hot engine parts and use caution when working under the car.