An LED tube lamp with overvoltage protection capability is provided. The LED tube lamp includes a lamp tube, two external connection terminals, a rectifying circuit, a filtering circuit, an LED module, and a protection circuit. The protection circuit is coupled between two input terminals of the LED module and configured to perform overvoltage protection when determining that a voltage level between the two input terminals of the LED module reaches or is higher than a predefined voltage value, wherein the protection circuit includes a diode and the predefined voltage value is in a range of about 40V to about 600V.