Over the past several years, uncooled IR detectors and focal plane arrays have been rapidly developed. Impressive progress has been made in both resistive microbolometers and pyroelectric thin-film detectors with noise equivalent temperature differences projected to be 10 to 20 mK with F/1 optics for such structures. Noise equivalent temperature of 50 mK bulk pyroelectric detectors and thin film resistive microbolometers are already demonstrated and in production. Other novel schemes, such as bimaterial capacitors, are also promising for uncooled IR detection. The US Army Research Laboratory is involved in developing ferroelectric materials to take advantage of the pyroelectric properties. The goal is to develop crystal oriented thin films to further improve detector performance. In this presentation, the operating principle of resistive microbolometers and pyroelectric detectors, and recent progress of uncooled RI focal plane arrays are discussed. In addition, the uncooled RI detector program at the Army Research Laboratory, that includes research facilities for and research efforts toward uncooled detectors and focal plane arrays is presented.