- 1 Keystone Mustard & Pickling Works
- 1 Keystone Paper Mills
- 1 Keystone Plaster Company
- 1 Keystone Saw, Tool & Steel Works-Henry Disston
- 1 Keystone Telephone Co.
- 1 Keystone Waist Co., The
- 1 Khan, Bairam, 1524?-1561
- 4 Khans (rulers)
- 1 Khid?r (Legendary character)
- 1 Kicking Horse Pass
- 1 Kimball and Gorton Car Manufacturers
- 1 Kimball Street
- 7 Kimball, Francis Hatch, Architect
- 32 Kimonos
- 3 Kindergarten School House
- 1 Kindness
- 4 King Iron Bridge & Manufacturing Co.
- 8 King of Prussia, Pennsylvania
- 1 King, Horatio Nelson, 1830-1895
- 4 King, Joseph Charles, ?1794-1854
- 9 King, Martin Luther, Jr.
- 1 King, William Excelsior Oil Works
- 1 Kingfishers
- 49 Kings
- 1 King's College London
- 1 Kings River
- 12 Kingsessing
- 10 Kingsessing Avenue
- 2 Kingsessing Hotel
- 2 Kingsessingville Inn
- 1 Kingsford Starch Exhibit
- 1 Kingsley, Charles, 1819-1875
- 5 Kingston, Jamaica
- 5 Kiosks
- 1 Kipper & Bianchi Woolens
- 6 Kiralfy, Bolossy, d. 1932, Architect
- 4 Kiralfy, Imre, 1845-1919, Architect
- 1 Kirby-Smith, Edmund, 1824-1893
- 2 Kirk, Chester Hughes, Architect
- 1 Kirkbride's Hospital see Pennsylvania Hospital for the Insane