LNP leader David Crisafulli's long-awaited decision on the issue comes on the same day the Albanese government's legislation passed the lower house of federal parliament.
"I have made up my mind: I won't be voting for the voice to be enshrined in the constitution," he told reporters on Wednesday.
"I note that the bill has just passed the lower house of parliament and I said I'd make my decision clear when I'd come to that decision.
"Having looked at the committee report, having looked at the prime minister's contribution in Adelaide, I'm just not convinced that is the best mechanism to deliver changes needed."
Mr Crisafulli's position echoes his federal counterpart Peter Dutton's stance against enshrining a national Indigenous voice in Australia's constitution.
The LNP leader said he would not campaign on the issue and instead keep his focus on Queensland issues.
"This is the first time I've commented on an issue in federal parliament.
"I've done so because I'm mindful that I'm in a leadership position and it's important I get my views across. I've done that and I've come to a considered view.
"I want the debate to be done with respect and decency and that's my contribution to it."
All state and territory leaders have thrown their in-principle support behind the voice including the sole Liberal, Tasmania's Jeremy Rockliff.
Queensland Premier Annastacia Palaszczuk supports a constitutional voice, saying it would help Australia "move forward as nation".
Mr Crisafulli has previously defended taking his time on announcing his position.
He said in April that a lot of Queenslanders would be taking their time to make an informed decision, and "I'm one of them".