The 2nd Seanad was in office in 1938. An election to Seanad Éireann, the Senate of the Oireachtas (Irish parliament), took place in March 1938, following the coming into operation of the Constitution of Ireland in December 1937. The senators served until the close of poll for the 3rd Seanad, in July 1938.

The Seanad of the Irish Free State was abolished by the Constitution (Amendment No. 24) Act 1936, with its last meeting on 19 May 1936. The Free State Seanad was elected in stages and thus considered to be in permanent session. Although there were five Seanad elections held before its abolition, the First Seanad includes the entire period from 1922 to 1936.

A new Seanad Éireann was established under the 1937 Constitution, with elections following general elections to Dáil Éireann. To indicate continuity with its Free State predecessor, the first Seanad elected after 1937 is numbered as the Second Seanad. The election to the 2nd Seanad was elected under Article 53 of the Constitution, which provided that on the coming into operation of the Constitution, which took place on 29 December 1937, a general election for the Seanad would take place as if there had been a dissolution of the Dáil.^[1]

On 27 April 1938, Seán Gibbons (FF) was proposed by Helena Concannon and seconded by Margaret Mary Pearse for the position of Cathaoirleach. Séamus Ó hEocha was proposed by Michael Hayes and seconded by Michael Tierney for the position. Gibbons was elected by a vote of 29 to 26.^[2]

On 11 May 1938, Pádraic Ó Máille (FF), who had served as Leas-Cheann Comhairle of Dáil Éireann from 1922 to 1927, was proposed by Seán Hayes and seconded by Peadar Toner Mac Fhionnlaoich for the position of Leas-Chathaoirleach. Ó Máille was elected by a vote of 30 to 23.^[3]

There are a total of 60 seats in the Seanad: 43 were elected on five vocational panels, 6 were elected from two university constituencies and 11 were nominated by the Taoiseach.

The following table shows the composition by party when the 2nd Seanad first met on 27 April 1938.

• Note: The entries for Senators who were elected or appointed to fill vacancies are shown in italics