An election to 43 of the 60 seats in Seanad Éireann, the senate of the Oireachtas (Irish parliament) took place in August 1977, following the 1977 general election to the 21st Dáil.

[1] The remaining 11 seats were occupied by nominees of Jack Lynch as Taoiseach.

He retained his seat in the Seanad, but resigned as Leas-Chathaoirleach on 12 July 1979.

Two of the Taoiseach's nominees joined Fianna Fáil before the first sitting of the Seanad.

[7] The following table shows the composition by party when the 14th Seanad first met on 27 October 1977.