Darling has signed on until 2020, while Barrass has re-signed with the club until 2019.
“We are delighted to have Jack and Tom extend their tenures with the club,” general manager of football Craig Vozzo said.
“Whilst at different stages of their careers, we are excited where both players can potentially take their games.
“Jack has already played 128 games and established himself as a quality AFL forward.
“He is a dedicated professional and we believe he can take his game to yet another level while Tom was terrific in his first full season of senior football.
“We believe that he has a lot of upside in his game and we look forward to assisting him evolve in coming seasons.”
Darling, 24, has kicked 228 goals in 128 games for the Eagles, while Barrass had a breakout year in 2016, playing 10 games and earning a rising star nomination.