| SURNAME | TOWNSHIP | RESEARCHER |
| Paddock | Sophia Preston | |
| Paddock | 1877-ca 1955 | Sharon (Paddock) Stang |
| Page | Linda Greenleaf | |
| Pahlke
website |
Barrington | Pattie Pahlke Schultz |
| Palmer | Rita Breeding | |
| Paquin | Highland Park 1916-1920 | CEhlers |
| Parker | Ruth Streed Filstead | |
| Parker | RN | |
| Patock | Laura Hewitt | |
| Peck | Lake County; 1880-? | Joyce Peck |
| Pederson | Sophia Preston | |
| Pennock | Waukegan | Jack King |
| Periolat | Long Grove/Palatine area; 1850s - ? | Diana Vickery |
| Peter | Antioch Twp | Terri Miller |
| Peterman/Petreman | Zion | Tracie (Hopkins) Boellner |
| Pettibone | Joe Bagg | |
| Pickle | Patricia Lanway Dowling | |
| Pillifant/Pellifant | Waukegan 1835-present | Philip Smith |
| Pollock | Kathy Kerr | |
| Portegys | Peggy Dado | |
| Porter | Volo, Lake County | Diane Porter Larson |
| Porteous | 1870s, Fremont Township | Karen Glass |
| Pratt
website |
Anne Kunzen | |
| Pratt | Wauconda | Barbara Pratt Opitz |
| Pratt
website |
Priscilla Ross-Fox | |
| Prell | Laura Doll | |
| Preston | Sophia Preston | |
| Price | Gilmer, Fremont Twp. | Carolyn Caflisch |
| Pullen | Antioch area | Jayne Adams Piehl |