The Jupiter ACE was a British home computer of the 1980s, marketed by a company named Jupiter Cantab. The company was formed by Richard Altwasser and Stephen Vickers, who had been on the design team for the Sinclair ZX Spectrum.

The Jupiter ACE somewhat resembled a ZX81 in a white case, with black rubber keys like the Spectrum. It displayed output on a television, and programs could be saved and loaded on cassette tape, as was standard at that time. The machine came with 3 KB RAM, expandable to 49 K. While it had only one video mode, text only, which displayed 24 rows of 32 columns of characters in black and white, it was possible to display graphics, by redefining the 8×8 pixel bitmap of any of the 128 characters. Like the ZX Spectrum, the machine's audio capabilities were restricted to beeps of programmable frequency and duration, output through a small built-in speaker.

The major difference from the 'introductory computer' that was the ZX81, however, was that the Jupiter ACE's designers, from the outset, intended the machine to be for programmers: the machine came with Forth as its default programming language. Though this gave a great speed advantage over the interpreted BASIC that was used on other machines, it did, along with the meager sound and graphics capabilities compared to the upcoming competition, keep the ACE squarely in a niche market. Sales of the machine were never very large; as of the early 2000's, surviving machines are quite uncommon, fetching quite high prices as collectors items.