Mercury Marine was founded by Carl Kiekhaefer in 1939 under the name of Kiekhaefer Corporation of Cedarburg WI. Mercury has consistently emphasized quality, performance, innovation and reliability. For example, in 1947 Mercury came out with their “Full-Jeweled Power” anti-friction ball, roller and needle bearings in all major bearing locations. In 1952 Mercury released a splined propshaft to end the problem of shearing pins. In 1961 Mercury introduced Mercruiser sterndrives to the Marine Industry. With the first sterndrive propulsion system with more than 100 HP Mercury also produced the first production outboard with 100 HP in 1962.

Mercury currently produces 2 and 4-stroke outboards. For 2-strokes you can purchase Mercury 75-250 hp engines. Mercury 4 strokes range from 2.5-300 HP.

SEI currently produces aftermarket replacement lower units (gearcases) for Mercury V6 both 2 and 4-stoke. SEI is currently working on replacements for the Mercury 4 and 3 cylinder Outboards.

Mercury Marine has several other brands as follows; Mercury and Mariner outboard engines; Mercury MerCruiser sterndrives and inboard engines; Mercury Racing high-performance outboards and sterndrives; MotorGuide trolling motors; Mercury and Teignbridge propellers; MotoTron electronic controls; Mercury inflatable boats; Mercury SmartCraft electronics; and Mercury and Quicksilver parts and oils. In 2006, Mercury Marine’s OptiMax engine was ranked "Highest in Customer Satisfaction with Two-Stroke Outboard Engines" by J.D. Power and Associates, and Mercury MerCruiser engines were ranked "Highest in Customer Satisfaction with Sterndrive Engines."