Post Offices in Waterloo, Iowa, United States SearchSearch SearchSearch View: Grid 1View: Grid 2View: Grid 3View: Grid 4View: Grid 5View: List Waterloo Post Office No Reviews Favorite Fax: (319) 274-2275Phone: (319) 274-2200Retail Hours Waterloo Annex Post Office No Reviews Favorite Phone: (319) 274-2200Retail Hours