What is the primary mythological source for Mercury, Venus, Mars, Jupiter, and Saturn?

Roman mythology

The majority of the named celestial bodies in the solar system—Mercury, Venus, Mars, Jupiter, and Saturn (the classical planets known for millennia)—derive their names directly from the Roman pantheon. These names are Latin borrowings that reflect the deities associated with specific planetary attributes, such as speed, beauty, war, kingship, and agriculture/time. While Roman mythology shares correspondences with Greek mythology (e.g., Mars is Ares), the specific names used in our modern sequence for these five planets are explicitly Roman (**Mercurius**, **Venus**, **Mars**, **Juppiter**, **Saturnus**). Uranus is the significant outlier among the major planets by explicitly referencing a Greek deity, Ouranos, rather than a Roman counterpart.