They say British institutions are being “battered by numerous prevailing winds”, including stretched finances and restrictions on international students, which could make it hard to sustain its position in the future.
The annual THE list looks at five areas: teaching, research quality, research environment, international outlook, and industry.
Of the UK universities in the top 200, 13 institutions improved their ranking in the past 12 months, five stayed the same, and seven dropped by at least one place.
Oxford was named the best-performing university globally, ahead of Massachusetts Institute of Technology (MIT) in the United States, which took second place.
The University of Cambridge took fifth place in the list, for the second year in a row, while Imperial College London fell from eighth to ninth place.