Portland is a city in Ionia County of the U.S. state of Michigan. The population was 3,883 at the 2010 census. The city is situated in the south central portion of Portland Township and is known as the "City of Two Rivers" since it is the confluence of the Grand River and the Looking Glass River. Portland is home to Portland Public Schools]and Portland Saint Patrick Catholic School and has been a Main Street Community]since 2003.