| Pinal | 484,200 | Casa Grande | Arizona | Phoenix-Tuscon, AZ | View → |
| Pine | 29,000 | Pine City | Minnesota | Minneapolis-St. Paul, MN | View → |
| Pinellas | 953,000 | St. Petersburg | Florida | Tampa, FL | View → |
| Pipestone | 9,100 | Pipestone | Minnesota | Sioux Falls-Rapid City, SD | View → |
| Piscataquis | 17,000 | Dover-Foxcroft | Maine | Portland-Bangor, ME | View → |
| Pitkin | 18,000 | Aspen | Colorado | Denver-Colorado Springs, CO | View → |
| Pitt | 175,000 | Greenville | North Carolina | Raleigh-Greenville-Wilmington, NC | View → |
| Pittsburg | 43,500 | McAlester | Oklahoma | Tulsa, OK-Fort Smith, AR | View → |
| Pittsylvania | 63,000 | Chatham | Virginia | Roanoke-Harrisonburg, VA | View → |
| Piute | 1,500 | Junction | Utah | Salt Lake City, UT | View → |
| Placer | 451,000 | Roseville | California | Sacramento, CA | View → |
| Plaquemines | 23,000 | Belle Chasse | Louisiana | New Orleans-Baton Rouge, LA | View → |
| Platte | 8,500 | Wheatland | Wyoming | Denver-Colorado Springs, CO | View → |
| Platte | 106,000 | Platte City | Missouri | Kansas City, MO | View → |
| Platte | 34,000 | Columbus | Nebraska | Omaha, NE-Sioux City, IA | View → |
| Pleasants | 7,600 | St. Marys | West Virginia | Wheeling-Clarksburg-Parkersburg, WV | View → |
| Plumas | 18,500 | Quincy | California | Sacramento, CA | View → |
| Plymouth | 530,000 | Brockton | Massachusetts | Boston-Springfield, MA | View → |
| Plymouth | 25,000 | Le Mars | Iowa | Omaha, NE-Sioux City, IA | View → |
| Pocahontas | 7,000 | Pocahontas | Iowa | Des Moines, IA | View → |
| Pocahontas | 8,400 | Marlinton | West Virginia | Roanoke-Harrisonburg, VA | View → |
| Poinsett | 24,000 | Harrisburg | Arkansas | Memphis, TN | View → |
| Pointe Coupee | 22,000 | New Roads | Louisiana | New Orleans-Baton Rouge, LA | View → |
| Polk | 42,000 | Cedartown | Georgia | Atlanta, GA | View → |
| Polk | 515,000 | Des Moines | Iowa | Des Moines, IA | View → |
| Polk | 31,000 | Crookston | Minnesota | Fargo, ND | View → |
| Polk | 20,500 | Columbus | North Carolina | Greenville, SC-Asheville, NC | View → |
| Polk | 51,000 | Livingston | Texas | Houston, TX | View → |
| Polk | 17,000 | Benton | Tennessee | Knoxville-Chattanooga, TN | View → |
| Polk | 5,200 | Osceola | Nebraska | Lincoln, NE | View → |
| Polk | 19,000 | Mena | Arkansas | Little Rock, AR | View → |
| Polk | 45,000 | Amery | Wisconsin | Minneapolis-St. Paul, MN | View → |
| Polk | 90,000 | Dallas | Oregon | Portland, OR | View → |
| Polk | 32,000 | Bolivar | Missouri | Springfield, MO | View → |
| Polk | 793,200 | Lakeland | Florida | Tampa, FL | View → |
| Pondera | 6,100 | Conrad | Montana | Missoula-Billings-Butte, MT | View → |
| Pontotoc | 38,500 | Ada | Oklahoma | Sherman, TX | View → |
| Pontotoc | 31,000 | Pontotoc | Mississippi | Tupelo-Meridian-Greenwood, MS | View → |
| Pope | 65,000 | Russellville | Arkansas | Little Rock, AR | View → |
| Pope | 11,000 | Glenwood | Minnesota | Minneapolis-St. Paul, MN | View → |
| Pope | 4,200 | Golconda | Illinois | Paducah, KY | View → |
| Poquoson City | 12,000 | Poquoson | Virginia | Norfolk, VA-Salisbury, MD | View → |
| Portage | 163,000 | Kent | Ohio | Cleveland-Youngstown, OH | View → |
| Portage | 71,000 | Stevens Point | Wisconsin | Green Bay, WI-Duluth, MN | View → |
| Porter | 175,000 | Valparaiso | Indiana | Chicago, IL | View → |
| Portsmouth City | 95,000 | Portsmouth | Virginia | Norfolk, VA-Salisbury, MD | View → |
| Posey | 25,000 | Mount Vernon | Indiana | Louisville, KY-Evansville, IN | View → |
| Pottawatomie | 74,300 | Shawnee | Oklahoma | Oklahoma City, OK | View → |
| Pottawatomie | 26,000 | Wamego | Kansas | Wichita, KS | View → |
| Pottawattamie | 93,000 | Council Bluffs | Iowa | Omaha, NE-Sioux City, IA | View → |
