UCAS, or the Universities and Colleges Admissions Service, is a charity and private limited company based in Cheltenham, England. It was established in 1992 from the merger of the Universities Central Council on Admissions (UCCA) and the Polytechnics Central Admissions System (PCAS), as well as the Standing Conference on University Entrance (SCUE). UCAS is responsible for managing the application process for undergraduate studies at British universities and colleges and also operates other admissions services including UCAS Conservatoires for performing arts, UCAS Teacher Training for postgraduate teacher training, and UCAS Postgraduate for some postgraduate courses.

The formation of UCAS was driven by the need to streamline and consolidate university admissions in the UK, which had previously been handled separately by UCCA since 1961 and PCAS since the 1980s. UCAS provides a variety of online application portals, search tools, and extensive free information and advice targeted at prospective students, current applicants, their parents or guardians, and educational staff assisting applicants.

UCAS is funded through fees collected from applicants and participating institutions, as well as advertising revenue. Its services are geared towards enhancing accessibility and efficiency in the higher education admissions process across the UK, ensuring a centralized and standardized application system.

Over the years, UCAS has expanded its scope to include more diverse educational sectors to meet the evolving needs of students and higher education providers.