Post offices in Mercer Island, WA

2 locations. Everything in Mercer Island.

• Mercer Island Post Office

  USPS

  3040 78th Avenue SE

  Mon–Fri8:30 am–5 pmSat10 am–2 pm
• The UPS Store

  UPS

  7683 Southeast 27th Street

  Mon–Fri7:30 am–5:30 pmSat9 am–5 pmSun10 am–4 pm