Full names of the Fab Four:

John Winston Lennon
(later changed Winston to Ono)

Sir James Paul McCartney
(Sir because he was knighted on March 11, 1997)

George Harrison
(according to Oxford Dictionary of National Biography, he didn't have a middle name but there are some biographies that states his middle name was Harold)

Richard Starkey
(there is much debate about Ringo's middle name.  Whether it's Henry, Parkin or Bright, you be the judge of that)