More than a dozen other soldiers and civilians were jailed for between two and 15 years, while Koba Kobaladze, a retired general, was cleared on the main charges and freed.
Georgian authorities had initially blamed the mutiny on its main enemy Russia, with which Georgia fought a war in August 2008.
The country's opposition accused the government of staging the rebellion to distract attention from protests that were then in progress against Saakashvili.
The event also came at the start of Nato military exercises in the former Soviet republic, condemned by Russia as "muscle-flexing".
The uprising was squashed around three hours after news of it broke, with Saakashvili following tanks and armoured personnel carriers into the base.