The Constitution of Luxembourg is the supreme law of the Grand Duchy of Luxembourg. The modern constitution was adopted on 17 October 1868.
Whilst the constitution of 1868 marked a radical change in Luxembourg's constitutional settlement, it was technically an amendment of the original constitution. That original constitution was promulgated on 12 October 1841,came into effect on 1 January 1842, and was acutely amended on 20 March 1848, and again on 27 November 1856.