Lobsang Tenzin, better known by the titles Professor Venerable Samdhong Rinpoche and to Tibetans as the 5th Samdhong Rinpoche (born 5 November 1939), is the Prime Minister (officially Kalon Tripa, or Chairman of the Cabinet), of the Central Tibetan Administration, or Tibetan government in exile, which is based in Dharamsala, India.

A close associate of the Dalai Lama, the Tibetan leader, he was elected to his current position in 2001.

Lobsang Tenzin was born in Jol, in eastern Tibet. At the age of five, he was recognised as the reincarnation of the 4th Samdhong Rinpoche and enthroned in Gaden Dechenling Monastery at Jol. Two years later he took vows as a monk, started his religious training at Drepung Monastery in Lhasa and completed it at the Madhyamika School of Buddhism. But in 1959, after the Chinese invasion of Tibet, he was forced to go into exile in India along with the 14th Dalai Lama, Tenzin Gyatso.

From 1960 onwards Lobsang Tenzin worked as a teacher in Tibetan religious schools in India, first in Simla and later in Darjeeling. Between 1965 and 1970 he was the Principal of Dalhousie Tibetan School and between 1971 and 1988 he was the Principal of Central Institute of Higher Tibetan Studies (CIHTS) at Varanasi (Benares), and from 1988 to 2001 he was the Director. He is regarded as one of the leading Tibetan scholars of Buddhism and is also an authority on the teachings of Mahatma Gandhi. He is fluent in both Hindi and English.

In 1991 Lobsang Tenzin was appointed by the Dalai Lama as a member of the Assembly of Tibetan People's Deputies, and later was unanimously elected as its Chairman. Between 1996 and 2001 he was an elected member of the Assembly representing exiled Tibetans from Kham province and also its Chairman.

In 2000 the Dalai Lama decided that the Tibetan people in exile should elect their own head of government, and in July 2001 Lobsang Tenzin was elected with about 29,000 votes, or about 84% of those cast. Jochen Thubten Namgyal, the other candidate, won the remainder. Since 2001 he has travelled extensively to gain support for the cause of Tibetan autonomy and raise awareness of the Dalai Lama's proposals for negotiating autonomy with the Chinese government.