- 1 Lounges (sitting rooms)
- 1 Lovatt, George Ignatius, Sr. (1872-1958), Architect
- 17 Love
- 1 Love blinded (Sculpture)
- 5 Love blinds (Sculpture)
- 4 Lovegrove & Co.
- 2 Lovejoy, Elijah P. (Elijah Parish), 1802-1837
- 1 Lovelace (Firm : Des Moines, Iowa)
- 1 Lovelace, Ada King, Countess of, 1815-1852
- 1 Lovering, Joseph S.
- 2 Love's First Whispers (Sculpture)
- 5 Love's messenger (Sculpture)
- 5 Love's net (Sculpture)
- 4 Low income housing
- 1 Lowe, James, d 1865
- 1 Lowell Bleachery
- 2 Lower Chichester Township
- 2 Lower Dublin Academy
- 3 Lower Dublin Hotel
- 30 Lower Merion Township, Pennsylvania
- 11 Low-rise buildings
- 1 Lowry Bros. Grocery Co.
- 1 Lowry Coffee Co.
- 1 Loxley Building
- 2 Loyering Barrel Factory
- 1 Luard, John Dalbiac, 1830-1860
- 2472 Lubin Manufacturing Company
- 14 Lubin, Siegmund, d. 1923
- 4 Lubricant
- 1 Lucas Varnish, Paint & Glass Co.
- 1 Lucas, Alice, 1855-
- 1 Lucas, Edgar, Mrs., 1855-
- 1 Lucifer (Sculpture)
- 1 Lucknow
- 3 Lucy, Saint, d. 304
- 30 Ludlow Street
- 1 Ludlow, James R. (James Reily), 1825-1886
- 2 Ludwick Building
- 8 Luggage
- 1 Luise Henriette, Electress, consort of Friedrich Wilhelm, Elector of Brandenburg, 1627-1667
