Check the Drain PlugThe drain plug is located at the bottom of the oil pan.
If the drain plug was not secured to the proper torque it may leak. Let the engine cool and check to see it if is at least finger tight. For precise tightening instructions, check your vehicle owner's manual.
The drain plug was cross threaded it may not seal completely.
The drain plug may also have a small rubber gasket that is missing. Check your owner's manual to see if you have all of the required pieces.
Check the Oil FilterThe oil filter can be located in several places throughout the engine compartment. Some are easy to find while others are tucked away where only elves can reach.
Check to see if the filter is tightened properly.
Check to see if the filter gasket is properly installed.