A parking assistance apparatus includes a display unit configured to display an image of an area around a vehicle; a sensor unit configured to detect at least one object around the vehicle; and at least one processor. The at least one processor is configured to perform an automatic parking function that moves the vehicle to a target parking position by: calculating a congestion level for the automatic parking function based on information about the at least one object around the vehicle detected by the sensor unit; and executing the automatic parking function according to the calculated congestion level.