The amendment makes New Jersey, one of the nation's highest-income and most expensive places to live, the 11th state to provide automatic cost-of-living increases and gives it one of the nation's 10 highest minimum wage rates.
It was on Tuesday's ballot after Republican Gov. Chris Christie earlier this year vetoed a bill to hike the minimum wage and start annual adjustments based on the Consumer Price Index, which measures how much consumers pay for goods and services.
Rather than accept Christie's alternative of a gradual phase-in of a minimum wage increase and no inflation increase, the Democrats who control the state Legislature decided to take the question to voters.
With 99 percent of precincts reporting, it had support of 61 percent of voters, according to unofficial returns.
A second ballot question, on allowing veterans groups to use games of chances such as bingo to pay for operating expenses, was adopted even more decisively, with support of 81 percent of voters, unofficial returns showed.
The minimum wage was backed by labor groups and liberal organizations.
"New Jersey sent a message to the rest of the country: Working poor should be a contradiction in terms," Kevin Brown, New Jersey Director of the Service Employees International Union Local 32BJ, said in a statement.
Business groups opposed not only the increase but also its adoption through a constitutional amendment and the future hikes. They say employees workers could be laid off so businesses can afford higher wages.
"The very New Jersey workers this aims to help, teenagers and low-skilled workers in particular, will be the ones hurt the most in the way of lost jobs and opportunity," Daryn Iwicki, New Jersey director of the pro-business, anti-tax group Americans for Prosperity, said in a statement.