Kendall Square Research (KSR) was a supercomputer company headquartered in Kendall Square in Cambridge, Massachusetts, near MIT. It was founded by Henry Burkhardt III who had previously helped found Data General and Encore Computer and was one of the original team that designed the PDP-8.

Its machines ran Unix, and were shared memory NUMA machines based on a custom processor.

A few of the KSR1 models were sold, but as the KSR2 was being rolled out, the company collapsed amid accounting irregularities involving the overstatement of revenue.

One customer of the KSR2, the Pacific Northwest National Laboratory, a United States Department of Energy facility, purchased an enormous pile of spare parts, and kept their machines running for years after the demise of KSR.

KSR, along with many of its competitors (see below) went bankrupt during the collapse of the supercomputer market in the mid-1990s.

KSR's competitors included Thinking Machines and Meiko, in addition to various old-line (and still surviving) companies like IBM, Intel, and Sun Microsystems.