An opto-isolator multi-voltage detection circuit is capable to handle a wide range of input voltages ranging from about 9 volts DC to about 240 volts AC includes an input voltage, an opto-isolator, a rectifier, a voltage divider, first and second transistors, and a DC to DC converter. The voltage divider operatively coupled to the first and second transistors is capable of evenly dividing the input voltage across the first and second transistors. The DC to DC converter operatively coupled to the transistors, the voltage divider, and the opto-isolator is capable of maintaining an output current from the rectifier. The use of the DC to DC converter, the voltage divider, and the transistors provide benefit of reducing a power dissipated throughout the entire circuit.