'Steinbutt' was a German attempt by the Abwehr intelligence service to establish links with the Welsh nationalist movement in the UK (early November 1940).

To this end the German intelligence organisation’s Abteilung II sabotage and special purposes department sent a pro-German Spaniard via Portugal to the UK to establish contact with the current leader of the Welsh nationalist movement, and to encourage him to begin a programme of anti-British sabotage.