Whistle joins from the WHL’s Kelowna Rockets, while Murphy returns for his eighth year with the club.
Having played his junior hockey in Britain, Whistle will count as a non-import player in the EIHL. He spent four seasons with the Rockets, backstopping them to the championship in 2014/15.
Murphy joined the Giants from Manchester Phoenix in 2009 and he has helped them clinch two regular season and one play-off title.
Steve Thornton, Giants’ Head of Hockey Operations, said: “I’m excited to bring Jackson Whistle to Belfast. First and foremost, he is an excellent goalie with impressive stats in the WHL for the Kelowna Rockets and helped them win the championship in 2015.
“He is a big goalie I expect him to compete with Stephen Murphy for the starting netminding duties this season.
“It is also great to have a Whistle back in Belfast with Jackson following in the footsteps of his father David who was the Giants’ inaugural coach and left a great legacy behind in Belfast, giving us two of our championship banners.
“The decision to sign Stephen Murphy is one of the easiest for me to make each year. Murphy has been the backbone of our organisation since I signed him back in 2009 and has backstopped us to a play-off title as well as two Elite League championships.”