Yes, you can wear a rain poncho over your backpack. In fact, many rain ponchos are specifically designed to accommodate backpacks -just look for ponchos with a generous size and extra length at the back to provide ample coverage for both you and your gear. Some ponchos have specialized features like backpack straps or loops to secure the poncho in place and prevent it from slipping off. This way, you can keep yourself and your backpack dry during rainy weather.