Étienne Constantin, Baron de Gerlache (26 December 1785 – 10 February 1871) was a lawyer and politician in the United Kingdom of the Netherlands, and later became in 1831 the first Prime Minister of the newly founded Belgian state. In 1831, he was elected in Liège for the Belgian Chamber of Representatives, of which he was president until 1832. Later on, he became the first 1st president of the Belgian Court of Cassation, a position he occupied until 1867. He died on 10 February 1871 in Ixelles.