He was born Castlefin, Co. Donegal. Growing up in County Tyrone he learned to play the fiddle. While studying engineering he heard the playing of piper RL O'Mealy from Belfast at an athletics meeting (in which he was a member of the Q.U.B. in the mile event) County Antrim, and he decided to take up that instrument. After moving to Dublin in the early thirties he became involved with the Gaelic League and together with pipers Breandán Breathnach and Tommy Reck he set about reviving the Piper's club which had not functioned for a number of years. Studying with John Potts (grandfather of Seán Potts), one of Ireland's greatest pipers at the time, he came into contact with other famous pipers such as Leo Rowsome and Johnny Doran. In 1950 he and a large group consisting of members of the Tulla Ceili Band and their followers, set up the first ever branch of the Pipers Club outside Dublin. The Pipers Club would very shortly afterwards bring about the formation of Comhaltas Ceoltóirí Éireann.
Working for Clare County Council he made the acquaintance of Crusheen man, fiddle player Mick Malone and Inagh man, Joe Leyden. Joe was the County Council clerk of works for the county and through him Seán Reid got to know every active traditional musician in the county. Through the travelling piper, Johnny Doran, he got to know of pipers Willie Clancy and Martin Talty. He promoted the revival of piping in Clare, bringing a group of Clare pipers to compete in the Oireachtas gathering annually in the 1940s and 1950s. In the late forties he played in the Tulla Céilí Band with Joe Cooley, before Cooley went to the United States. From 1950 until the formation of the Pipers Club he worked to promote the Comhaltas Ceoltóirí Éireann (CCE) in county Clare and Munster. After many years of waiting for CCE to devote a greater effort to reviving the uilleann pipes he, and a small group of like minded pipers decided that it was "now or never" and so proceeded, much to the annoyance of CCE, to formally set up the Dublin Pipers Club, an organisation that would foster and promote the uilleann pipes to ensure it would survive. In 1998 the Sean Reid society was founded to promote Uillean pipe scholarship.