For the second time in three years Voss has come under early pressure after his NAB CUP-winning Lions have battled to a 2-3 start.
They are about to face a nightmare eight-match stretch in which they face six of last year's eight finalists, as well as Carlton and red-hot Essendon.
Holmes said Voss would be given the full 22 rounds to prove his worth and said he would not be drawn into a running commentary on the coach's future.
"We're very supportive of Vossy," Holmes said.
"He's the coach of our side and we'll leave the decision until the end of the year and let him focus on winning football games.
"My view is he's doing a very, very good job in developing a young list. He's acutely aware of the job at hand. He's hard working and you couldn't question his work ethic and footy nous.
"As far as we're concerned we'll leave it to the end of the year."
Holmes rejected the notion Voss was coaching for his football future over the approaching two-month stretch, saying the draw evened out in the final nine weeks to favour the Lions.
While not elaborating, he said there was more to consider than wins and losses.
The Lions won 10 games in 2012.
"We knew there was going to be a tough period in the middle of the year, but you need to look at it in its entirety," Holmes said.
"You look at the last nine games and you'd say eight of them are very winnable. You can't just look at bits and pieces of the fixture, you need to look at it as a whole."
Full-back Daniel Merrett said the players were letting the Lions down, not Voss.
"We're here to do a job. He's our coach and what's let us down is our performances as players," Merrett said.
"We've been quite off at times and not putting a consistent effort in."
The Lions play the Swans in Sydney on Sunday.
Michael Whiting covers Brisbane Lions news for AFL.com.au. Follow him on Twitter: @AFL_mikewhiting
