Nigel Mattison's birth name is Nigel James Mattison.
Mr.Campbell
Nigel Lythgoe goes by Nasty Nigel.
Nigel is not a character from the books. But there is Nigel in the movies (Gof, OOTP). He is Potter's fans, Harry is Nigel's idol.
Nino Bellini's birth name is Giovanni Bellin.
Shyne's birth name is Jamal Barrow.
Nigel Tangye's birth name is Nigel Trevithick Tangye.
Nigel Benn's birth name is Nigel Gregory Benn.
Nigel Balchin's birth name is Balchin, Nigel Marlin.
Nigel Ash's birth name is Nigel Ezekiel Ash.
Nigel Davenport's birth name is Arthur Nigel Davenport.
Nigel Farrell's birth name is Nigel George Farrell.
Nigel Chapman's birth name is Nigel Conrad Chapman.
Nigel Clough's birth name is Nigel Howard Clough.
Nigel Planer's birth name is Nigel George Planer.
Nigel Patrick's birth name is Nigel Dennis Wemyss.
Nigel Hamilton's birth name is Charles Nigel Hamilton.
Nigel Havers's birth name is Nigel Allan Havers.