A thermal management system for a vehicle may include a cooling apparatus configured to include a radiator, a first water pump, a first valve, and a reservoir tank to circulate a coolant in the coolant line to cool at least one electrical component provided in the coolant line; a battery cooling apparatus including a battery coolant line connected to the coolant line through a second valve, and a second water pump and a battery module which are connected through the battery coolant line; a chiller provided in the battery coolant line between the second valve and the battery module, and connected to a refrigerant line of an air conditioner; and a heating circuit including a heater which is connected to the coolant line and the chiller through first and second connection lines to supply a coolant having a temperature which is increased while passing through the at least one electrical component.