||In this study, an uplink light-emitting diode (LED) beacon that can enable a CubeSat to locate a laser communication ground station was designed, constructed, and tested, and detection of the beacon from low Earth orbit (LEO) with a CMOS camera on the AeroCube-5 CubeSat was demonstrated. The LED beacon described is an alternative to the near-infrared laser beacons commonly used in laser communication systems, and has the potential to be cheaper, easier to point, and to require less regulatory coordination than a laser beacon, while performing the same function. An optical design is detailed, consisting of an array of 80 green LEDs with a center wavelength of 528 nm, producing 15.9 watts of free-space optical power, focused to a beamwidth of 8.12 degrees full-widthhalf-max (FWHM). A link budget is presented that shows the beacon is detectable by a CubeSat-mounted camera with a 7.9 mm diameter aperture and a silicon CMOS detector. A prototype beacon comprised of an LED array, focusing optics, thermal control, and tracking mechanisms was designed and constructed, and laboratory measurements of the beam profile and optical power of the prototype beacon using an optical power meter are presented herein. A field test is also described, in which the beacon was deployed at Wallace Astrophysical Observatory in the early morning of May 15, 2017 and imaged with a camera on AeroCube-5. The array is successfully identified in a sequence of five images taken by the CubeSat, demonstrating the viability of LED uplink beacons with CubeSat imagers.