Born and reared in Aill na Brún, near Cill Ciaráin in Conamara, Seosamh is marriued to Treasa ní Loideáin of Roisín na Mainíoch, Carna. They have four children.

He works with Raidió na Gaeltachta, a station he was instrumental in setting up.

His involvement in community affairs in Connemara and Aran goes back to the foundation of the Gaeltacht Civil Rights Movement in 1969.

Founding member of the Gaeltacht Civil Rights Movement.

He believes Galway County Council needs a wake-up call from Connemara.

Elected Independent member of the Údará na Gaeltachta.
1999 Election Report - "There was no doubting who was most pleased on Sunday, however, as any number of recounts was never going to upset Independent candidate Seosamh Ó Cuaig whose first preference vote took him to second place on the table and almost elected him on the first count. As it was he took the second seat."
Re-elected in 2005.

Elected to Galway Co Council in 2004, re-elected 2009.