Ultimate Kronos Group (UKG) is an American multinational technology company with dual headquarters in Lowell, Massachusetts, and Weston, Florida. It provides workforce management and human resource management services. The company was founded in April 2020 as a result of the merger of Ultimate Software and Kronos Incorporated. Former Kronos CEO Aron Ain was the CEO and chairperson of the combined company until July 1, 2022, when he stepped down as CEO to become Executive Chairperson.