Is an unlicensed driver automatically at fault in an auto accident in Washington state?

No. Just the fact of being unlicensed does not mean that the driver did something that caused the accident. Being unlicensed is what is called a non-moving violation. Another violation of this type may be not having a current registration tag on the vehicle. Just because you don't have a tag on your car doesn't automatically make you At Fault for someone hitting your car. Fault for the accident will have to be determined by the police officers after they investigate the scene and take statements from witnesses. The person who is driving without a drivers license will get a ticket for not being licensed and then whoever was at fault will receive a violation for whatever they did to cause the accident.