Gaius Valerius Flaccus was a Roman general, politician and statesman. He was consul of the Roman Republic in 93 BC and a provincial governor in the late-90s and throughout the 80s. He is notable for his balanced stance during the Sullan civil wars, the longevity of his term as governor, and his efforts to extend citizenship to non-Romans.

Lucius Valerius Flaccus became suffect consul of the Roman Republic in 86 BC when Gaius Marius, the consul prior, unexpectedly died. He was elected to complete Marius's term in office. Marius had fought a series of civil wars against Lucius Cornelius Sulla, both leaders of their respective factions: the populares and the optimates. Flaccus was considered a staunch supporter of Marius and Lucius Cornelius Cinna; the leaders of the Marian-Cinna faction within the populares. Cinna was Marius's consular collegae and succeeded Marius as faction leader.