[2] The exterior of the Missouri State Capitol is notable for its architectural features: the Baroque dome, loosely modeled after St. Peter’s basilica in Rome, rising 238 feet (73 m) above ground level, topped by sculptor Sherry Fry’s bronze statue of Ceres, the Roman goddess of agriculture; the eight 48-foot (15 m) columns on the south portico; the six 40-foot (12 m) columns on the north portico; the 30-foot (9 m)-wide grand staircase; and the bronze entrance doors, each 13 by 18 feet (4.0 m × 5.5 m)—at the time, the largest cast since the Roman era.

A prime attraction is a series of murals painted by Thomas Hart Benton in the House Lounge.

The grand staircase is flanked by large heroic bronze statues of Meriwether Lewis and William Clark, and the third-floor rotunda is the site of the Hall of Famous Missourians, a group of bronze busts of prominent Missourians honored for their achievements and contributions to the state.

Statuary is a prominent feature of the capitol’s grounds: heroic allegorical bronze figures sculpted by Robert Aitken (representing Missouri's two great rivers—the Mississippi and the Missouri), and a 13-foot (4 m) tall statue of Thomas Jefferson made by James Earle Fraser dominate the south entrance.

Sculptor Karl Bitter’s bronze relief, depicting the signing of the Louisiana Purchase by Livingston, Monroe and Marbois, and Weinman’s Fountain of the Centaurs are features of the north grounds.

The present location on top of the bluffs in current Jefferson City was chosen because it afforded the best view of the Missouri River of any place which they had seen within the limits prescribed by the Constitution.

The fourth state capitol (and the first in Jefferson City) was made out of brick, two stories tall, measured approximately 40 by 60 feet (12 m × 18 m), and took two years to complete.

The fifth capitol (which was at the current site) was completed in 1840 as designed by Stephen Hills for approximately $350,000 (equivalent to $10,682,000 in 2023), with some controversies and claims that there were bribes and kickbacks.

This was approved in a general election / referendum by the public by a three-to-one margin, however, the state miscalculated on incoming revenue projections, and ended up collecting $4,215,000 (equivalent to $137,830,500 in 2023).

All of this money was eventually used for the entire monumental project, which is one of the reasons why the sculptures and artwork are of such high caliber of quality and beauty.

The style makes many historical references to the national United States Capitol on Capitol Hill in Washington, D.C., as well as to ancient Greek and Roman temples; however, the typical column capital top is a unique variation on the canonical Corinthian style capital, replacing the acanthus leaves with local flora.

In November 2006, the 9,000 lb (4,100 kg) dome chandelier, which had been lowered almost to the floor for maintenance, fell the remaining five feet.