Terry Hutt has been waiting outside the Lindo Wing at St Mary’s Hospital for the past 13 days in the hopes of seeing the new royal baby.
Mr Hutt said he was "over the moon" and that the Duke and Duchess' baby will be "healthy".
Having camped outside hospitals for the arrival of previous royal babies, Mr Hutt said he "knows the routine".
"I think she's going to come out about three or four o'clock if she gets the okay for herself and the baby," he predicted.
The Takasakiyama Natural Zoological Garden in Oita is now considering renaming Charlotte after complaints from the Japanese public.
Kensington Palace warning over 'harassment' around Sandringham where Kate and William are staying with princess Charlotte and prince George.
Naming the royal baby Charlotte Elizabeth Diana will be seen as a tribute to the Duke of Cambridge's father, mother and grandfather.