Phelps County
Also known as Phelps County, Missouri, Phelps County, MO
county in Missouri, United States
Key facts
- Country
- United States
- State
- Missouri
- Founded
- November 13, 1857
- Named after
- John S. Phelps
- Seat
- Rolla
- Largest city
- Rolla
- Total
- 674 sq mi (1,750 km )
- Land
- 672 sq mi (1,740 km )
- Water
- 2.5 sq mi (6.5 km ) 0.4%
- Estimate 2025
- 45,247
- Density
- 66.4/sq mi (25.6/km )
- Time zone
- UTC−6 ( Central )
- Summer dst
- UTC−5 ( CDT )
Article
Old county courthouse, listed on the National Register of Historic Places
Phelps County is a county in the central portion of the U.S. state of Missouri. As of the 2020 United States census, its population was 44,638. The largest city and county seat is Rolla. The county was organized on November 13, 1857, and was named for U.S. Representative and Governor of Missouri John Smith Phelps.