@Smashley Wedge Antilles and an un-named Y-Wing pilot were shown to have survived. There may also have been another 8 Y-Wings which went into the attack, but were not shown destroyed, so some of those pilots might have survived too.
A later games and a book which introduced new characters who were supposedly likely to be involved (in their own contexts that didn’t exist when the first film was made) have suggested that the known surviving Y-Wing pilot is either Keyan Farlander (if you believe the computer game
X-Wing from LucasArts, published in 1992) or Evaan Verlaine (if you believe the book