Arie "Aad" Kosto (born 9 January 1938) is a retired Dutch politician of the Labour Party (PvdA) and jurist.

After the election of 1989 Kosto was appointed as State Secretary for Justice in the Cabinet Lubbers III, taking office on 7 November 1989.

On 13 November 1991 Kosto was targeted by the radical activist group Revolutionary Anti-Racist Action (RaRa) who destroyed his house in Grootschermer with a bomb.

[1] Kosto was appointed as Minister of Justice following the resignation of Ernst Hirsch Ballin, taking office on 27 May 1994.

[2] Kosto retired from active politic and became active in the public sector and occupied numerous seats as a nonprofit director on several boards of directors and supervisory boards (Stichting Pensioenfonds Zorg en Welzijn, Copyright and Patent association, Institute for Multiparty Democracy) and served on several state commissions and councils on behalf of the government (Probation Agency and the Custodial Institutions Agency)