Yes, you can replace a 1157 bulb with an LED. There are a few things to keep in mind when doing so, however. First, make sure that the LED is compatible with the socket type of the 1157 bulb. Second, check the voltage and amperage requirements of the LED before connecting it to the 1157 socket. Finally, be aware that some LEDs may not be fully compatible with all functions of a 1157 bulb (such as brake light or turn signal). If this is the case, use only those LEDs that are specifically designed for compatibility with a 1157 bulb.