The new minimum wage - €7.65 an hour - will come into effect on Tuesday February 1. The €1 cut was announced in the Budget in December.
The move follows the signing of the order today by the Minister for Enterprise, Trade and Innovation Batt O'Keeffe.
The Minister said the move to reduce the rate would help improve the country's competitiveness.
Figures show that about 47,000 workers - 3.1% of the employed labour force - are paid at or below the current adult experienced worker rate of €8.65 an hour.
IBEC, the group that represents Irish business, today said the move to reduce the minimum is necessary to support economic recovery and create employment.
It pointed out that the revised rate will be about 49% of the average industrial wage, which is well ahead of the OECD average of 39%.
