| McLeod | 35,000 | Hutchinson | Minnesota | Minneapolis-St. Paul, MN | View → |
| McMinn | 54,000 | Athens | Tennessee | Knoxville-Chattanooga, TN | View → |
| McMullen | 700 | Tilden | Texas | San Antonio-Corpus Christi, TX | View → |
| McNairy | 25,700 | Selmer | Tennessee | Memphis, TN | View → |
| McPherson | 500 | Tryon | Nebraska | Lincoln, NE | View → |
| McPherson | 2,400 | Eureka | South Dakota | Sioux Falls-Rapid City, SD | View → |
| McPherson | 29,500 | McPherson | Kansas | Wichita, KS | View → |
| Meade | 29,000 | Brandenburg | Kentucky | Louisville, KY-Evansville, IN | View → |
| Meade | 29,500 | Sturgis | South Dakota | Sioux Falls-Rapid City, SD | View → |
| Meade | 4,300 | Meade | Kansas | Wichita, KS | View → |
| Meagher | 1,900 | White Sulphur Springs | Montana | Missoula-Billings-Butte, MT | View → |
| Mecklenburg | 1,120,000 | Charlotte | North Carolina | Charlotte-Greensboro, NC | View → |
| Mecklenburg | 31,000 | South Hill | Virginia | Raleigh-Greenville-Wilmington, NC | View → |
| Mecosta | 44,000 | Big Rapids | Michigan | Traverse City, MI | View → |
| Medina | 182,400 | Medina | Ohio | Cleveland-Youngstown, OH | View → |
| Medina | 53,000 | Hondo | Texas | San Antonio-Corpus Christi, TX | View → |
| Meeker | 23,000 | Litchfield | Minnesota | Minneapolis-St. Paul, MN | View → |
| Meigs | 23,350 | Pomeroy | Ohio | Charleston-Bluefield, WV | View → |
| Meigs | 13,500 | Decatur | Tennessee | Knoxville-Chattanooga, TN | View → |
| Mellette | 2,100 | White River | South Dakota | Sioux Falls-Rapid City, SD | View → |
| Menard | 2,000 | Menard | Texas | Austin-Waco, TX | View → |
| Menard | 12,600 | Petersburg | Illinois | Champaign-Peoria, IL | View → |
| Mendocino | 91,000 | Ukiah | California | San Francisco, CA | View → |
| Menifee | 6,600 | Frenchburg | Kentucky | Lexington-Bowling Green, KY | View → |
| Menominee | 23,000 | Menominee | Michigan | Green Bay, WI-Duluth, MN | View → |
| Menominee | 4,700 | Keshena | Wisconsin | Green Bay, WI-Duluth, MN | View → |
| Merced | 290,000 | Merced | California | Fresno, CA | View → |
| Mercer | 8,400 | Beulah | North Dakota | Bismarck, ND | View → |
| Mercer | 58,500 | Princeton | West Virginia | Charleston-Bluefield, WV | View → |
| Mercer | 41,900 | Celina | Ohio | Cincinnati-Dayton, OH | View → |
| Mercer | 109,000 | Hermitage | Pennsylvania | Cleveland-Youngstown, OH | View → |
| Mercer | 15,000 | Aledo | Illinois | Davenport, IA-Moline, IL | View → |
| Mercer | 3,700 | Princeton | Missouri | Des Moines, IA | View → |
| Mercer | 22,000 | Harrodsburg | Kentucky | Lexington-Bowling Green, KY | View → |
| Mercer | 387,340 | Trenton | New Jersey | Philadelphia, PA | View → |
| Meriwether | 21,500 | Greenville | Georgia | Atlanta, GA | View → |
| Merrick | 7,800 | Central City | Nebraska | Lincoln, NE | View → |
| Merrimack | 160,000 | Concord | New Hampshire | Boston-Springfield, MA | View → |
| Mesa | 165,000 | Grand Junction | Colorado | Denver-Colorado Springs, CO | View → |
| Metcalfe | 10,300 | Edmonton | Kentucky | Lexington-Bowling Green, KY | View → |
| Miami | 108,700 | Troy | Ohio | Cincinnati-Dayton, OH | View → |
| Miami | 35,500 | Peru | Indiana | Indianapolis-Fort Wayne, IN | View → |
| Miami | 35,000 | Paola | Kansas | Kansas City, MO | View → |
| Miami-Dade | 2,732,800 | Miami | Florida | Miami-West Palm Beach, FL | View → |
| Middlesex | 1,650,000 | Cambridge | Massachusetts | Boston-Springfield, MA | View → |
| Middlesex | 162,200 | Middletown | Connecticut | Hartford, CT-Providence, RI | View → |
| Middlesex | 863,162 | New Brunswick | New Jersey | New York, NY | View → |
| Middlesex | 11,000 | Saluda | Virginia | Richmond, VA | View → |
| Midland | 180,000 | Midland | Texas | El Paso-Odessa, TX | View → |
| Midland | 83,000 | Midland | Michigan | Grand Rapids, MI | View → |