Lyonpo Sangay Ngedup (Dzongkha: སངས་རྒྱས་དངོས་གྲུབ, Wylie: sangs-rgyas dngos-grub, born 1 July 1953) was Prime Minister of Bhutan from 1999 to 2000 and again from 2005 to 2006.

In 1976, he joined the Bhutanese foreign service, and attended diplomatic courses in Australia and New Delhi.

In his presidential debate, the first ever held in February 2008, Lyonpo Sangay Ngedup has promised that, if he wins the election, he would base his policies of governing on Gross National Happiness (GNH), a philosophy (coined by the fourth king Jigme Singye Wangchuck, his brother-in-law) that states that happiness is more important than material growth for the people.

In 2002 he undertook with six other members the Move for Health Walk from Trashigang to the capital city of Thimphu covering on foot a distance of 560 km concluded successfully as scheduled.

The Walk was conceived by Lyonpo Sangay Ngedup to promote the fund-raising for the Bhutan Health Trust Fund Archived 2008-06-15 at the Wayback Machine, an important initiative to keep the primary health services of Bhutan free of charge.