| Oakes, Kevin | President | US | Republican | 1 |
| Oakes, Kevin | U.S. House | PA | NPA | 1 |
| Oakley, Imani Raine | U.S. House | NJ | Democratic | 1 |
| Oatman, Laura | U.S. House | CA | Democratic | 1 |
| Obern, Lawrence Anthony II | President | US | UNK | 1 |
| Obernolte, Jay | U.S. House | CA | Republican | 1 |
| Obert, Kelsten C | U.S. House | CA | Republican | 1 |
| Oberweis, Jim | U.S. House | IL | Republican | 2 |
| Obler, Gil Mr. | U.S. House | NY | Green | 1 |
| Obrien, James Richard Sr | President | US | Republican | 1 |
| Obrien, Joshua | U.S. House | MD | Libertarian | 1 |
| O'Brien, Michael | U.S. House | PA | Democratic | 1 |
| O'Brien, William Lawrence | U.S. Senate | NH | Republican | 2 |
| O'Callaghan, Conor | U.S. House | AZ | Democratic | 1 |
| Ocampo Grajales, David | U.S. House | NJ | Democratic | 1 |
| Ocasio-Cortez, Alexandria | U.S. House | NY | Democratic | 1 |
| Ocegueda, Adrian | U.S. Senate | TX | Democratic | 1 |
| O'Connell, Austin Luther | U.S. House | CO | Republican | 1 |
| O Connell, Bruce | U.S. House | NC | Republican | 1 |
| O'Connell, Ford | U.S. House | FL | Republican | 1 |
| O'Connor, Daniel Jay | U.S. House | OH | Democratic | 1 |
| O'Connor, Daniel Jay Jr. | U.S. House | OH | Democratic | 1 |
| O'Connor, Kevin J | U.S. Senate | MA | Republican | 1 |
| O'Connor, Shawn Patrick Patrick | U.S. House | NH | Independent | 1 |
| October, President Quinci Pryce | President | US | Republican | 1 |
| O'Cull, Sayre Christian | U.S. House | KY | Democratic | 1 |
| Oddo, Joseph | U.S. House | SC | OTH | 1 |
| O'Dea, Joseph Matthew | U.S. Senate | CO | Republican | 2 |
| O''Dear, Craig S | U.S. Senate | MO | Independent | 1 |
| O'Dell, Linda | U.S. House | MI | Democratic | 1 |
| O''Dell, Shannon May | U.S. Senate | FL | Republican | 1 |
| Odom, Wanda Carol | President | US | Republican | 1 |
| Odom, Wanda Ms. | President | US | Republican | 1 |
| O'Donnell, Andrew Joesph | President | US | UN | 2 |
| O'Donnell, Christine | U.S. Senate | DE | Republican | 1 |
| O'Donnell, James D | U.S. House | NY | Republican | 1 |
| O'Donnell, John Robert | U.S. House | AZ | Democratic | 1 |
| O'Donnell, Justin F | U.S. Senate | NH | Libertarian | 1 |
| O'Donnell, Marty | U.S. House | NV | Republican | 1 |
| O'Donnell, Ronald | U.S. House | CA | Democratic | 2 |
| O'Donnell, Sherrell Anne | U.S. Senate | MI | Republican | 1 |
| O'Donnell, Sherry Anne Dr | U.S. House | MI | Republican | 1 |
| O'Dowd, Dan | U.S. Senate | CA | Democratic | 1 |
| Odulate, Andalib Mimokunmi Thomas | U.S. House | MD | Democratic | 1 |
| Oelke, Elena | U.S. House | MI | Republican | 1 |
| Offical, President Quinci Pryce | President | US | Republican | 1 |
| of the United States Of, President Qui | President | US | Republican | 1 |
| O''Gabhann, James C. III | U.S. House | IN | Democratic | 1 |
| Ogilvie, Lee Aleck | U.S. House | FL | Republican | 1 |
| Ogle, James Orlando III | President | US | Libertarian | 1 |
| Ogle, Michael Allen | U.S. House | KS | Republican | 1 |
| Ogles, Andy | U.S. House | TN | Republican | 2 |
| Ogles, Brandon Thomas | U.S. House | TN | Republican | 1 |
| Oglesby, Dennis | U.S. House | MO | Democratic | 1 |
| O'Grady, Casey Sims | U.S. Senate | SC | Republican | 1 |
| O'Halleran, Tom | U.S. House | AZ | Democratic | 1 |
| Ohanian, Grant Ethridge Mr | President | US | Democratic | 1 |
| O'Hara, Joseph | U.S. House | GA | Democratic | 1 |
| O'Hara, Tim | U.S. House | OH | Republican | 1 |
| Ohlson, Daniel Albert Mr Jr | President | US | Independent | 1 |
| Ohtaki, Peter | U.S. House | CA | Republican | 1 |
| Ohtaki, Peter I | U.S. House | CA | Republican | 1 |
| Oh, Thomas | U.S. House | VA | Republican | 1 |
| Ojeda, Richard | U.S. Senate | WV | Democratic | 1 |
| Ojeda, Richard Neece II | President | US | Democratic | 1 |
| Ojeda, Richard Neece Senator II | U.S. House | WV | Democratic | 1 |
| O''Kalani, Keiki | President | US | Independent | 1 |
| O'Keefe, John | President | US | Democratic | 1 |
| Okpa, Ejike | U.S. House | TX | Republican | 1 |
| Okugo, Cecilia | President | US | Republican | 1 |
| Olaniyi, Noah O | President | US | OTH | 1 |
| O'Leary, Ryan | U.S. House | IA | OTH | 1 |
| Oler, Travis | U.S. Senate | ID | Democratic | 1 |
| Olikara, Steven | U.S. Senate | WI | Democratic | 1 |
| Oliva Jr, Phil | U.S. House | NY | Republican | 1 |
| Olivas, Laura Mrs. | U.S. House | NM | NPA | 1 |
| Olivas, Miguel | U.S. House | AZ | Democratic | 1 |
| Oliver, Brittany T | U.S. House | MD | Democratic | 1 |
| Oliver, Chase Russell | U.S. House | GA | Libertarian | 1 |
| Oliver, Chase Russell | President | US | Libertarian | 1 |
| Oliver, Julie Lynn | U.S. House | TX | Democratic | 3 |
| Oliver, Malcolm Khalid | President | US | Democratic | 1 |
| Oliver, Melvin Russell Mr. | U.S. House | GA | Democratic | 1 |
| Olivo, Christine Alexandria | U.S. House | FL | Democratic | 1 |
| Olivo, Christine Alexandria | U.S. House | FL | NPA | 1 |
| Olkowski, Christopher J | President | US | Republican | 1 |
| Olmack, Jeramy | U.S. House | VA | NON | 1 |
| Olmack, Jeramy Lee | U.S. House | VA | NPA | 1 |
| Olscamp, David Michael | President | US | Democratic | 1 |
| Olsen, Erik | U.S. House | WI | Republican | 1 |
| Olsen, Martin | U.S. House | TN | Democratic | 1 |
| Olsen, Robert | U.S. House | AZ | Democratic | 1 |
| Olsen, Robert Dean | U.S. House | AZ | Democratic | 2 |
| Olsen, Travis | U.S. House | TX | Democratic | 1 |
| Olson, Brayden | U.S. House | WA | Democratic | 1 |
| Olson, Charles Lee Mr. Jr | President | US | NNE | 1 |
| Olson, Craig | U.S. House | ME | Democratic | 1 |
| Olson, Evan Andrew | U.S. House | AZ | Independent | 1 |
| Olson, Jeffrey E | U.S. House | FL | Republican | 1 |
| Olson, John Richard | U.S. House | OK | Democratic | 1 |
| Olson, Justin | U.S. House | AZ | Republican | 1 |
| Olson, Justin | U.S. Senate | AZ | Republican | 1 |
| Olson, Kimberly D | U.S. House | TX | Democratic | 1 |
| Olson, Nancy Lynn | U.S. House | HI | Republican | 2 |
| Olson, Peter G. | U.S. House | TX | Republican | 1 |
| Olson, Reed Jerrold | U.S. House | MN | DFL | 1 |
| Olson, Richard Thomas | U.S. House | MN | W | 2 |
| Olson, William | U.S. House | FL | Republican | 1 |
| Olszewski, Al | U.S. House | MT | Republican | 1 |
| Olszewski, John Anthony Jr. | U.S. House | MD | Democratic | 1 |
| Olukore, Ade Oba | President | US | APF | 1 |
| Olukore, Ade Oba | President | US | APF | 1 |
| Oluwadare, Blessing T | U.S. House | MD | Democratic | 1 |
| Oluwadare, Blessing T | U.S. House | MD | Democratic | 2 |
| O'Malley, Martin Joseph | President | US | Democratic | 1 |
| O'Mara, William Edward Dr IV | U.S. House | CA | Democratic | 1 |
| Omar, Ilhan | U.S. House | MN | DFL | 1 |
| Omere, Iroghama C | U.S. House | TX | Democratic | 1 |
| Omere, Iroghama Christianna Ms. | U.S. House | NY | Independent | 1 |
| Omoruyi, Kenneth Ehiosu | U.S. House | TX | Republican | 1 |
| Omphroy, Anika | U.S. House | FL | Democratic | 1 |
| Onder, Robert for Jr. | U.S. House | MO | Republican | 1 |
| Onder, Robert Frank Jr | U.S. House | MO | Republican | 1 |
| Oneil, Josiah | U.S. House | CA | Republican | 1 |
| O'Neill, Paul Robert | President | US | UNK | 1 |
| O'Neill, Ruby Dr. | U.S. House | CT | Republican | 1 |
| O'Neil, Rusten | U.S. Senate | CA | Independent | 1 |
| Ontiveros, Desiree | U.S. House | LA | Democratic | 1 |
| Onyejiaka, Diana Chioma | U.S. Senate | TN | Democratic | 1 |
| Opela, Michael Paul Mr. Sr. | U.S. House | WI | Republican | 1 |
| Oppegaard-Peltier, Ernest Joseph Mr III | U.S. House | MN | DFL | 1 |
| Oppenheim, Jeffrey | U.S. House | TX | Republican | 1 |
| Oram, Albert | U.S. House | FL | NPA | 1 |
| O'Reilly, Michael | U.S. House | NY | Republican | 1 |
| Orentlicher, David | U.S. House | IN | Democratic | 1 |
| Oristian, Michael Patrick | U.S. House | CA | Republican | 1 |
| Orlinski, John | U.S. Senate | WA | Republican | 1 |
| Ornelas, Robert | U.S. House | AK | OTH | 1 |
| O'Rourke, Michael Joseph | U.S. House | FL | Republican | 1 |
| O'Rourke, Robert (Beto) | U.S. Senate | TX | Democratic | 1 |
| O'Rourke, Robert Beto | President | US | Democratic | 1 |
| Orozco, Stevens | U.S. House | TX | Democratic | 1 |
| Orr, Patrick | U.S. House | SC | Republican | 1 |
| Ortagus, Morgan | U.S. House | TN | Republican | 1 |
| Ortega, Michael | U.S. House | CA | Democratic | 1 |
| Ortiz, Gabriel | U.S. House | NC | Democratic | 1 |
| Ortiz, Jonathan | U.S. House | NY | Democratic | 1 |
| Ortiz, Oscar | U.S. House | CA | Democratic | 1 |
| Ortiz, Rafael Arturo Mr. | U.S. House | FL | Republican | 1 |
| Ortiz, Sergio E | U.S. House | FL | Republican | 2 |
| Ortman, Julianne | U.S. Senate | MN | Republican | 1 |
| Orts, Eric | U.S. Senate | PA | Democratic | 1 |
| Ortt, Robert G | U.S. House | NY | Republican | 1 |
| Orwig, Teresa | U.S. House | OR | Republican | 1 |
| Osborn, Dan | U.S. Senate | NE | Independent | 2 |
| Osborne, Anthony Mr | U.S. House | MO | Democratic | 1 |
| Osborne, Ethan Keith | U.S. House | KY | OTH | 1 |
| Osborne, Jacob Nathaniel | U.S. House | TX | Democratic | 1 |
| Osborne, John E. | U.S. Senate | TN | Republican | 1 |
| Osborne, Joseph Darren | U.S. House | NC | Republican | 1 |
| Osborn, Kirk Lloyd | U.S. House | TX | Republican | 1 |
| Oseguera, Hector Omar Jr. | U.S. House | NJ | Democratic | 1 |
| O'Shea, Catherine Anne Ms | U.S. House | IL | Republican | 1 |
| O'Shea, John | U.S. House | TX | Republican | 1 |
| O'Shea, Michael | U.S. House | NC | Democratic | 1 |
| Osifeso, Aderinola | President | US | Republican | 1 |
| Osoria, Lola | U.S. House | NY | Democratic | 1 |
| Osorio, Bryan | U.S. House | CA | Democratic | 1 |
| Osornio, Angel | President | US | Independent | 1 |
| Ossoff, T. Jonathan | U.S. Senate | GA | Democratic | 1 |
| Osta, Sami Michel N/A | U.S. House | FL | AIC | 1 |
| Osterbach, Rachel Peggy | President | US | OTH | 1 |
| Osuchukwu, Onyekachi | U.S. Senate | MD | Independent | 1 |
| Ota, Henry Alan Mr | U.S. House | CA | FS | 1 |
| Otman, Alejandro Ariel Mr | U.S. House | SC | Independent | 1 |
| Ottaway, Brent M | U.S. House | PA | Democratic | 1 |
| Ottinger, Keith | President | US | Republican | 1 |
| Ott, Michael James Mr. | President | US | Independent | 1 |
| Ouariti, Adam | President | US | Democratic | 1 |
| Outlaw, Dana Edwards | U.S. House | NC | Democratic | 1 |
| Overby, Lucas | U.S. House | FL | LPF | 1 |
| Overby, Paula Mirare | U.S. Senate | MN | DFL | 1 |
| Overton, Matthew August | U.S. House | WA | Republican | 1 |
| Oviatt, Nicholas | U.S. House | NE | Republican | 1 |
| Owen, Peter | U.S. House | FL | Democratic | 1 |
| Owens, Burgess | U.S. House | UT | Republican | 2 |
| Owensby, Alexandra Dr. | U.S. House | KY | Democratic | 1 |
| Owens, H Douglas | U.S. House | UT | Democratic | 1 |
| Owens, Hubert Jr | U.S. House | MD | Republican | 1 |
| Owens, Kyle Lee Master | U.S. House | IL | Independent | 1 |
| Owens, Michael Claude | U.S. House | GA | Democratic | 1 |
| Owens, Michael Dr | U.S. House | GA | Democratic | 1 |
| Owens, Michael R | U.S. House | NC | Republican | 1 |
| Owens, William | U.S. House | NY | Democratic | 1 |
| Owen, William Timothy | U.S. Senate | WA | Republican | 1 |
| Oz, Mehmet Dr | U.S. Senate | PA | Republican | 2 |