The RMS-099 Rick Dias (RMS-099 リック・ディアス Rikku Diasu?) is a second-generation mass-production attack-use mobile suit introduced in the anime Mobile Suit Zeta Gundam.

Developed by Anaheim Electronics, the RMS-099 (MSA-099, MSA-009) Rick Dias became one of the first mass-produced mobile suits of the AEUG's Zeta Project for their fight against the corrupt Titans. Because many engineers who worked on the Rick Dias were former Principality of Zeon members, the Rick Dias featured many similarities to Zeon mobile suits such as a mono-eye sensor. Originally, the Rick Dias ("Dias" is derived from Bartolomeu Dias, the Portuguese explorer who first rounded the Cape of Good Hope) was supposed to be called γ Gundam (Gamma Gundam) as it is built out of the new Gundarium γ. This material was developed by Axis and has strength similar to standard Gundarium yet weighs less, making the suit lighter and thus allowing it to accommodate a greater fuel capacity.

The Rick Dias is one of the earlier mobile suits to use the 360-degree panoramic cockpit, and the first original design to be constructed by the AEUG. One notable feature is that unlike other mobile suits at the time, the cockpit of the Rick Dias is built into its head and not the chest. Built into its hands are specialized launchers that can be used to launch fire-suppressing gas or a binding adhesive. For combat, the Rick Dias can be equipped with a variety of weapons, making it a versatile mobile suit. Among its built-in weapons include 55mm vulcan phalanx in its head and a beam saber stored on the underside of a backpack-mounted rack. For ranged combat, the Rick Dias is equipped with a pair of beam pistols stored in the backpack-mounted rack. It can also be optionally equipped with a clay bazooka and a beam rifle.