Shamseddine was born Nasreddin Moustapha Shamesedin in the village of Joune, in the southern part of the Chouf mountains. As a young man, he spent time in Alexandria and Cairo unsuccessfully looking for work in films. He returned to Beirut and joined the choir of the Lebanese state radio.

In the late 1950s, he joined the Lebanese Popular Troupe of the Rahbani brothers, but left in 1961 to embark on a solo career.

Shamseddine performed with Fairuz from 1961 until the civil war in 1975. His last appearance was in 1979 in Petra.