Here are the Russian Orthodox saints that start with the letter "P," with their feastdays where available:
- Pachomius the Great, also known as Pachomios the Great, May 15
- Pachomios the New Martyr, April 16
- Paesis, March 11
- Paissy Velichkovsky
- Paissy of the Far Caves, November 4
- Palestine, One Hundred Fifty-Six Martyrs of, September 17
- Palestine, Thirty-Three Holy Martyrs of, August 16
- Palestine, Three Virgins of, November 5
- Palladius, January 28
- Pambo the Ascetic, July 18
- Pamphilius of Palestine, November 5
- Pamphilius the Presbyter, February 16
- Panayiotes the New Martyr, June 24
- Pankraty the Hieromonk of the Far Caves, February 9
- Panteleimon the Great Martyr and All-Merciful, July 27
- Paphnuty of the Far Caves, February 15
- Paphnutius of Jerusalem, April 19
- Paraskeva the Great Martyr, October 28
- Paraskeva the New, October 14
- Paraskeva the Wonderworker of Pinega, October 28
- Paraskeva of Rome, July 26
- Paraskeva Petka of Serbia, October 14
- Pardus the Solitary, December 15
- Parthenius, Patriarch of Constantinople, March 24
- Parthenius of Lampsakos, February 7
- Pasha of Birsk, November 21
- Patapios, December 8
- Patermuthius of Palestine, September 17
- Patrick of St. Savas Monastery, March 20 and May 16
- Patrick of Ireland
- Paul and Juliana the Martyrs
- Paul the Apostle, June 29
- Paul, Spiritual Father of St. Theodora of Sihla
- Paul of Caesarea, July 16 and 18
- Paul of Jamnia, February 16
- Paul of Komelsk, also known as Paul of Obnora, January 10
- Paul the Obedient of the Far Caves, September 10
- Paul the Russian, April 3
- Paul of Tobolsk, November 4
- Paula the Martyr
- Pelagia of Diveyevo, January 30
- Pelagia of Jerusalem
- Pelagia of Tarsus
- Peleus of Palestine, September 17
- Peter the Apostle, June 29
- Peter the Aleut
- Peter of Alexandria, November 24
- Peter of Evandrou, July 1
- Peter the Iberian, December 1
- Peter of Rostov, June 29
- Peter of Sebastea, January 9
- Peter Absalom, January 12
- Phanourios the Newly-Manifest, August 27
- Philaret the Merciful, December 1
- Philip the Apostle, November 14
- Philip Metropolitan of Moscow, January 9
- Philonilla the Martyr
- Philosoph Ornatsky, July 20
- Philosophos, May 1
- Philothei of Athens, February 19
- Photini the Samaritan Woman, February 26
- Photios the Great, February 6
- Pimen the Faster of the Far Caves, August 27
- Pimen the Ill of the Kiev Caves, August 7
- Pinna the Martyr
- Pior the Anchorite of the Far Caves, Cheesefare Saturday
- Polycarp, Bishop of Smyrna, February 23
- Polycarp the Hagioloist, July 24
- Polydorus of Cyprus, September 3
- Polyeuctus, January 9
- Porphyrius, Bishop of Gaza, February 26
- Porphyrius, Martyr, February 16
- Porphyrius, September 15
- Porphyrius the Mime, November 19
- Probus, December 19
- Prokhor the Wonderworker of the Far Caves, February 10
- Procopius the Fool-For-Christ, July 8
- Procopius the Martyr of Palestinian Caesarea, July 8
- Procopius of Sazava, September 16
- Procopius of Ustiug, July 8
- Procopius of Vyatka, December 21
- Puplius, January 25
Source: http://www.gnisios.narod.ru/lives.html