Engelhardt is an American maker of laminated upright basses and cellos founded in 1969 as the Engelhardt-Link Company by former Valco employees Bob Engelhardt and Allen Link. When Kay Musical Instrument Company's parent Valco dissolved, Engelhardt-Link bought the upright bass and cello tooling at auction and continued production in Elk Grove Village, Illinois, carrying forward Kay's '69 model designations with the addition of an "E" prefix to part numbers.

The lineup centered on plywood (laminated) double basses built for durability and projection rather than the refined tone of carved instruments, making them a longtime fixture in school orchestras, jazz combos, bluegrass bands, and rockabilly stages. Core models included the Maestro series (EM-1, EM-2), the Concert series with gamba corners (EC-1), and the Swingmaster series (ES-9), the latter directly descended from the Kay S-9 and prized by jazz and slap-style players. Engelhardt also produced student cellos in similar laminated construction.

In 2019 the company's tooling, jigs, molds, and brand were acquired by Upton Bass String Instrument Company in Connecticut, which has used the original Kay-era forms to inform new designs such as the Upton Chicago bass. Engelhardt instruments remain widely circulated on the used market and are commonly the first "real" upright owned by working bassists in jazz, bluegrass, and country music.

Engelhardt has 2 products cataloged on Equipboard, including Upright Basses. Their gear is featured by 1 artist, with the strongest followings in Rock and Folk, World, & Country. Notable users include Bob Crawford.