The source of Stephen is the Greek name Stephanos.
This name was borrowed into English long enough ago that the intervocalic [f] sound was voiced to become [v].
This is a regular sound change that was also responsible for some other f~v alternations in English, such as loaf~loaves .
However, in the name Stephen
the spelling "ph" remained (or has been restored) due to the influence of the Greek original.
In other words, Stephen and Steven are exactly the same name, but the former merely has an anachronistic spelling.
english.stackexchange.com/users/48/JSBձոգչ
I always found interesting that both "phial" and "vial" exist in English, having a common origin but different pronunciations.
OED lists "vial" as an alteration of "phial"; the "ph" is originally Greek.
Does this count?
english.stackexchange.com/users/1304/CesarGon
Is there any other instance of "ph" being pronounced as "v" in either American or British English?
In British English, nephew can be pronounced nev -yoo .
english.stackexchange.com/users/1871/ghoppe
Stephen is of Greek origin (Stephanos).
The ph is unusual in its v pronunciation.
The only possibility I can think of is that it arrived in English via Spanish, where it is spelt 'Esteban'.
The Spanish pronunciation of 'b' is somewhere between English 'V' and 'B'.
In Hungarian it is spelt 'Istvan', so there's another possible source.
english.stackexchange.com/users/None/
Born in London, I have always pronounced nephew with a 'v' sound.
Locals in Essex (England) also pronounce the village name of Bulphan as 'Bulvan' rather than 'Bulfan', even though the second syllable is derived from the word fen.
english.stackexchange.com/users/9204/Paul
"STEVEN" is the canon pronunciation because Old English make-shift gender phonetics are applied to the E-PH.
However in common rumor, a user of the name may be required to know the two pronunciations presented by text key models in probable instances rendering it differently pronounced than that of the "V" spelling.
http://babynames.net/names/stephen
english.stackexchange.com/users/313316/Stephen Edward Waterstram
While I know how  my  name is pronounced, I've run into many non-native english speakers who have stumbled over this unique exception to English.  Even in the female name, "Stephanie", the  ph  is pronounced as  f .  What is the etymology of "Stephen" and is there any other instance of  ph  being pronounced as  v  in either American or British English?
Why is the "ph" pronounced like a "v" in "Stephen"? Is this the only word like that?
english.stackexchange.com
<etymology><pronunciation><proper-nouns>
english.stackexchange.com/questions/9772
english.stackexchange.com/users/3433/Stephen Furlani
The name Stephen comes from the Greek name Stephanos and was borrowed into English long enough ago that the f-sound became a v. In this sense, the ph is unusual in its pronunciation, although in London, "nephew" can be pronounced with a 'v' sound. Because of its Greek origin and the intervocalic [f] sound was voiced as [v], Stephen is pronounced as with a "v". Some believe it may be due to Spanish origin of the name as "Esteban" which "b" in English is "v". There are other words of Greek origin that such as "phial" which is pronounced and spelt "vial" in English. Some suggest that Old English phonetics might have dictated the sound.
The name Stephen comes from the Greek name Stephanos and was borrowed into English long enough ago that the f-sound became a v. In this sense, the ph is unusual in its pronunciation, although in London, "nephew" can be pronounced with a 'v' sound. Stephen comes from the Greek name Stephanos, and the ph shifted from an [f] to a [v] sound in Old English. This shift can also be seen in loaf/loaves, or the British English variant pronunciation of nephew.
The source of  Stephen  is the Greek name Stephanos. "phial" and "vial"  both exist in English, have a common origin but different pronunciations. In Britian, nephew can be pronounced with a V sound. This is a regular sound change that was also responsible for some other f~v alternations in English, such as  loaf~loaves . The name "Stephen" comes from the Greek name "Stephanos". Other instances of a "ph" becoming a "v" sound include "phial" and "vial" and the word "nephew".
I always found interesting that both "phial" and "vial" exist in English, having a common origin but different pronunciations. OED lists "vial" as an alteration of "phial"; the "ph" is originally Greek. However in common rumor, a user of the name may be required to know the two pronunciations presented by text key models in probable instances rendering it differently pronounced than that of the "V" spelling. Born in London, I have always pronounced nephew with a 'v' sound. In other words, Stephen and Steven are exactly the same name, but the former merely has an anachronistic spelling. In Hungarian it is spelt 'Istvan', so there's another possible source. Locals in Essex (England) also pronounce the village name of Bulphan as 'Bulvan' rather than 'Bulfan', even though the second syllable is derived from the word fen. The only possibility I can think of is that it arrived in English via Spanish, where it is spelt 'Esteban'. The Spanish pronunciation of 'b' is somewhere between English 'V' and 'B'.
Because of its Greek origin and the intervocalic [f] sound was voiced as [v] There are other instances in English where "ph" is pronounced as "v" It is becasue of Old English
Stephen comes from the Greek name Stephanos, and the ph shifted from an [f] to a [v] sound in Old English. This shift can also be seen in loaf/loaves, or the British English variant pronunciation of nephew.
The name "Stephen" comes from the Greek name "Stephanos". Other instances of a "ph" becoming a "v" sound include "phial" and "vial" and the word "nephew".