| Mifflin | 46,500 | Lewistown | Pennsylvania | Harrisburg, PA | View → |
| Milam | 25,000 | Cameron | Texas | Austin-Waco, TX | View → |
| Millard | 13,000 | Fillmore | Utah | Salt Lake City, UT | View → |
| Mille Lacs | 26,000 | Milaca | Minnesota | Minneapolis-St. Paul, MN | View → |
| Miller | 6,000 | Colquitt | Georgia | Jacksonville-Tallahassee, FL | View → |
| Miller | 45,000 | Texarkana | Arkansas | Shreveport, LA | View → |
| Miller | 24,500 | Eldon | Missouri | Springfield, MO | View → |
| Mills | 4,800 | Goldthwaite | Texas | Austin-Waco, TX | View → |
| Mills | 15,000 | Glenwood | Iowa | Omaha, NE-Sioux City, IA | View → |
| Milwaukee | 950,000 | Milwaukee | Wisconsin | Milwaukee, WI | View → |
| Miner | 2,300 | Howard | South Dakota | Sioux Falls-Rapid City, SD | View → |
| Mineral | 900 | Creede | Colorado | Denver-Colorado Springs, CO | View → |
| Mineral | 4,600 | Hawthorne | Nevada | Las Vegas-Reno, NV | View → |
| Mineral | 4,300 | Superior | Montana | Missoula-Billings-Butte, MT | View → |
| Mineral | 28,000 | Keyser | West Virginia | Washington, DC | View → |
| Mingo | 23,000 | Williamson | West Virginia | Charleston-Bluefield, WV | View → |
| Minidoka | 23,000 | Rupert | Idaho | Boise-Pocatello, ID | View → |
| Minnehaha | 215,000 | Sioux Falls | South Dakota | Sioux Falls-Rapid City, SD | View → |
| Missaukee | 15,000 | Lake City | Michigan | Traverse City, MI | View → |
| Mississippi | 37,000 | Blytheville | Arkansas | Memphis, TN | View → |
| Mississippi | 14,000 | Charleston | Missouri | Paducah, KY | View → |
| Missoula | 122,000 | Missoula | Montana | Missoula-Billings-Butte, MT | View → |
| Mitchell | 11,000 | Osage | Iowa | Cedar Rapids, IA | View → |
| Mitchell | 14,500 | Spruce Pine | North Carolina | Greenville, SC-Asheville, NC | View → |
| Mitchell | 22,000 | Camilla | Georgia | Jacksonville-Tallahassee, FL | View → |
| Mitchell | 8,900 | Colorado City | Texas | Lubbock-Abilene, TX | View → |
| Mitchell | 6,300 | Beloit | Kansas | Wichita, KS | View → |
| Mobile | 420,700 | Mobile | Alabama | Mobile, AL-Panama City, FL | View → |
| Modoc | 8,700 | Alturas | California | Medford, OR | View → |
| Moffat | 13,000 | Craig | Colorado | Denver-Colorado Springs, CO | View → |
| Mohave | 224,000 | Kingman | Arizona | Phoenix-Tuscon, AZ | View → |
| Moniteau | 16,000 | California | Missouri | Springfield, MO | View → |
| Monmouth | 644,489 | Freehold | New Jersey | New York, NY | View → |
| Mono | 14,500 | Bridgeport | California | Las Vegas-Reno, NV | View → |
| Monona | 9,000 | Onawa | Iowa | Omaha, NE-Sioux City, IA | View → |
| Monongalia | 107,000 | Morgantown | West Virginia | Pittsburgh-Erie, PA | View → |
| Monroe | 760,000 | Rochester | New York | Buffalo-Rochester-Syracuse, NY | View → |
| Monroe | 13,000 | Union | West Virginia | Charleston-Bluefield, WV | View → |
| Monroe | 8,000 | Albia | Iowa | Des Moines, IA | View → |
| Monroe | 154,000 | Monroe | Michigan | Detroit, MI-Toledo, OH | View → |
| Monroe | 145,000 | Bloomington | Indiana | Indianapolis-Fort Wayne, IN | View → |
| Monroe | 46,000 | Sweetwater | Tennessee | Knoxville-Chattanooga, TN | View → |
| Monroe | 6,500 | Clarendon | Arkansas | Little Rock, AR | View → |
| Monroe | 28,000 | Forsyth | Georgia | Macon-Columbus, GA | View → |
| Monroe | 46,000 | Sparta | Wisconsin | Madison-La Crosse, WI | View → |
| Monroe | 84,000 | Key West | Florida | Miami-West Palm Beach, FL | View → |
| Monroe | 20,900 | Monroeville | Alabama | Mobile, AL-Panama City, FL | View → |
| Monroe | 10,500 | Tompkinsville | Kentucky | Nashville, TN | View → |
| Monroe | 171,000 | Stroudsburg | Pennsylvania | Scranton, PA-Binghamton, NY | View → |
| Monroe | 34,500 | Waterloo | Illinois | St. Louis, MO | View → |
