A heat pump system for a vehicle, the heat pump system comprising: a cooling apparatus including a first radiator, a first pump, a first valve, and a second valve which are connected through a coolant line, 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 first valve, and a second radiator, a second pump, and a battery module which are connected through the battery coolant line to circulate the coolant in the battery module; and a chiller connected to a first connection line, which is connected to the battery coolant line between the second radiator and the battery module, and a second connection line connected to the first valve, and connected to a refrigerant line of an air conditioner through a refrigerant connection line, to adjust a temperature of the coolant by performing heat exchange between the coolant which is introduced in the chiller and a refrigerant which is selectively supplied from the refrigerant line of the air conditioner; characterized by: a heating apparatus including a heating line connected to the coolant line through the second valve to heat a vehicle interior by use of the coolant and a third pump and a heater provided on the heating line; and a third connection line having a first end portion connected to the chiller, and a second end portion connected to the second valve so that the coolant that has passed through the at least one electrical component or the heating apparatus is selectively supplied to the chiller through operation of the second valve. a cooling apparatus including a first radiator, a first pump, a first valve, and a second valve which are connected through a coolant line, 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 first valve, and a second radiator, a second pump, and a battery module which are connected through the battery coolant line to circulate the coolant in the battery module; and a chiller connected to a first connection line, which is connected to the battery coolant line between the second radiator and the battery module, and a second connection line connected to the first valve, and connected to a refrigerant line of an air conditioner through a refrigerant connection line, to adjust a temperature of the coolant by performing heat exchange between the coolant which is introduced in the chiller and a refrigerant which is selectively supplied from the refrigerant line of the air conditioner; characterized by: a heating apparatus including a heating line connected to the coolant line through the second valve to heat a vehicle interior by use of the coolant and a third pump and a heater provided on the heating line; and a third connection line having a first end portion connected to the chiller, and a second end portion connected to the second valve so that the coolant that has passed through the at least one electrical component or the heating apparatus is selectively supplied to the chiller through operation of the second valve. a heating apparatus including a heating line connected to the coolant line through the second valve to heat a vehicle interior by use of the coolant and a third pump and a heater provided on the heating line; and a third connection line having a first end portion connected to the chiller, and a second end portion connected to the second valve so that the coolant that has passed through the at least one electrical component or the heating apparatus is selectively supplied to the chiller through operation of the second valve.