P55

P55 or P-55 may refer to:

Vessels

 * ARA Zurubí, a patrol boat of the Argentine Navy
 * HMS Unsparing (P55), a submarine of the Royal Navy
 * HMNZS Wellington (P55), a patrol vessel of the Royal New Zealand Navy
 * INS Sharda (P55), a patrol vessel of the Indian Navy

Other uses

 * Curtiss-Wright XP-55 Ascender, an American experimental fighter aircraft
 * Intel P55, a computer chipset
 * Papyrus 55, a biblical manuscript
 * PIK3R3, phosphatidylinositol 3-kinase regulatory subunit gamma
 * Tumor necrosis factor receptor 1
 * P55, a state regional road in Latvia