P61 or P-61 may refer to:
Vessels , a patrol boat of the Royal Bahamas Defence Force , a submarine of the Royal Navy , a corvette of the Indian Navy , an offshore patrol vessel of the Irish Naval Service
Polemistis (P61), a HSY-55-class gunboat of the Hellenic Navy
Other uses Northrop P-61 Black Widow, an American night fighter aircraft BRM P61, a Formula One racing car P61 road (Ukraine) Papyrus 61, a biblical manuscript P61, a state regional road in Latvia Sea Tiger (P61), a fictional submarine in the film We Dive at Dawn P61, three-dimensional space group number 169