P23

P23, p23, P-23, or P.23 may refer to:

• p23, the protein encoded by the PTGES3 gene
• The Piaggio P.23, an Italian transport aircraft prototype of 1935
• The Piaggio P.23R, an Italian transport aircraft prototype of 1936 of a design unrelated to that of the Piaggio P.23
• PZL P.23, the designation of prototypes of the PZL.23 Karaś, a Polish light bomber and reconnaissance aircraft produced from 1936 to 1938
• XP-23 Hawk, a fighter aircraft of the U.S. Army
• LÉ Aisling (P23), Irish warship