Alexander "Alex" Papaconstantinou (Greek: Άλεξ Παπακωνσταντίνου; born 29 December 1979 in Brännkyrka, Sweden), is a Swedish songwriter and music producer of Greek origin. He has worked with a number of artists including Antique, Elena Paparizou, Arash, Anna Vissi, Cameron Cartio and Sarbel. In 2011, Papaconstantinou adopted the production pseudonym Alex P and started collaborating with record producer RedOne, co-writing and co-producing the Enrique Iglesias hit song "I Like How It Feels". He has since joined RedOne's production and 2101 songs writing team and co-wrote and co-produced the Khaled album C'est la vie,. Along with Adam Baptiste, he has also been credited as a featured artist under the name "The WAV.s".

His sister is television presenter Ritza Papaconstantinou.