Shamrock 13
- Brand: Shamrock
- Fruit: Lemons
- Packing House: Placentia Mutual Orange Association
- City: Placentia
- County: Orange
- State: California
- Scarcity Rating: Rare
- Image Donor: Gielijn Escher
- Printer's Inscription: LITHO IN U.S.A. - WESTERN LITHO. CO. LOS ANGELES