Tüdeviin Üitümen (Mongolian: Түдэвийн Үйтүмэн, internationally often Tudev Ujtumen; born 27 August 1939) is a Mongolian chess master. He became Mongolia's first International Master in 1965.
In 1969, he won the West Asian zonal tournament in Singapore. He tied for 20th-22nd in the Interzonal tournament at Palma de Mallorca 1970 (Robert James Fischer won).
In other international tournaments, he took 15th at Sochi 1964 (Chigorin mem, Nikolai Krogius won); took 15th at Sochi 1965 (Chigorin mem, Wolfgang Unzicker and Boris Spassky won); took 9th at Havana 1967 (4th Armies-ch, Vlastimil Hort won); tied for 11-13th at Tbilisi 1971 (Goglidze mem); and took 9th at Dubna 1973 (Mikhail Tal and Ratmir Kholmov won).
Ujtumen was a three-time winner of the Mongolian Chess Championship, in 1972, 1978 and 1986. He played six times for Mongolia in Chess Olympiads (1964-1974). He won the individual gold medal on second board (+11 −1 =5) at Tel Aviv 1964 and silver on second board (+12 −3 =3) at Siegen 1970.