The new National Living Wage (NLW) has come into force, requiring employers to pay workers aged 25 and over at least £7.20 an hour.
It is expected to give around 1.3 million UK workers an immediate pay rise.
The policy was announced by the Conservatives in last summer's Budget by Chancellor George Osborne, in an effort to create a higher-wage, lower-welfare economy.
Workers aged 21 to 24 will continue to be entitled to the National Minimum Wage of £6.70 an hour.
Leader of the Welsh Conservatives, Andrew RT Davies, said:
"The launch of the national living wage is further proof that Conservatives are on the side of hardworking people who want to get on in life.
"Millions across the UK will see their wages rise today as a result of the chancellor’s reforms; whilst the reforms will also be a welcome boost for 150,000 Welsh workers by 2020.
"Conservatives in government are making work pay by increasing personal allowances, capping benefits and now we have gone further by ensuring that Welsh workers receive the living wage."
Shadow Economy Minister, William Graham, said:
"While Jeremy Corbyn’s Labour Party has rejected every opportunity to put money in people’s pockets by rejecting a council tax freeze, opposing tax cuts and wasting public money on an airport, we believe people can spend their money better than politicians.
"After 17 years of successive Labour governments, Wales remains the poorest part of the UK with many people on low wages, trapping them in poverty.
"This sends a clear message that Conservatives are working to tackle unfair pay and set a clear example to all employers to value and invest in their staff.
"Welsh Conservatives are a party of aspiration, who want to help people get on in life."