According to the United States Census Bureau, the township has a total area of 18.0 square miles (46.6 km2), all land.

Ugstad Road runs north–south along Midway Township's eastern boundary line with adjacent city of Proctor.

Russell Road runs north–south along Midway Township's eastern boundary line with adjacent city of Duluth.

Saint Louis River Road runs east–west along Midway Township's northern boundary line with adjacent city of Hermantown.

Skyline Parkway passes through the southeast portion of Midway Township.

15.8% were of German, 15.3% Swedish, 14.9% Norwegian, 10.6% Finnish, 7.4% Polish, 6.3% Irish and 5.1% French ancestry according to Census 2000.