William also talks about his joy at becoming a father during the ITV programme which will be screened next month.
The Duke spoke about his son on Wednesday during an appearance at an agricultural show on Anglesey, describing Prince George as a “pretty loud but of course very good-looking”.
William, an RAF search and rescue helicopter pilot, also confirmed he would be leaving his Anglesey home and moving “elsewhere” when his military posting on the Welsh island comes to an end next month.
He has almost completed his three-year tour of duty and is widely expected to return to London with Kate and son George to take on more royal duties rather than stay in the service.
A spokeswoman for ITV said: “Prince William also talks about his love of Africa, his commitment to wildlife conservation and his hope that Prince George will one day share these passions.
“He explains the pivotal part that Africa has played in his life and reflects on continuing a royal legacy in the continent, building on his father’s conservation work and Princess Diana’s humanitarian campaigns.”
The documentary – Prince William’s Passion: New Father, New Hope – is being produced by Spun Gold TV in partnership with the broadcaster CNN.