The deals were announced Friday but the Eagles elected not to disclose the lengths of any of the extensions.
However, AFL.com.au understands that Kennedy has signed until the end of the 2016 season.
All three players finished in the top five of the Eagles best and fairest count in 2013 with Priddis claiming the inaugural John Worsfold Medal in the same year he received life membership at the club.
Kennedy topped the club's goalkicking with 60 for the season and was selected in the All Australian 40-man squad.
The 21-year-old Darling finished in the top five of the club's best and fairest for the second year in succession after kicking 42 goals. He will be a pivotal player in the Eagles' future.
"It is great to have three quality players and outstanding individuals extend their commitment to the club," Eagles' football operations manager Craig Vozzo said.
"We see all three players as very important to our plan of improving as quickly as possible.
"We hold them all in very high regard and are delighted they have extended their commitment to the club."
