will priority mail be delivered on saturday depends on the specific USPS service used. For most locations within the United States, USPS Priority Mail delivers 1-3 business days, including Saturdays, with no additional charges. USPS Priority Mail Express, which is an expedited service, also delivers on Saturdays, even for overnight shipments. However, standard First-Class Mail and other non-priority services may not deliver on Saturdays unless the service is upgraded to a more expedited option. Always check the shipping timeline and service terms when choosing the shipping method to ensure timely delivery.