MADRID—Spain’s second-quarter unemployment rate fell to 22.4%, the lowest level since 2011, as the eurozone’s fourth-largest economy benefited from higher tourism and labor-market liberalization policies to create jobs at the fastest quarterly pace in the country’s history.

Spain’s National Statistics Bureau said on Thursday that the number of people without jobs fell by 295,600 in the quarter to 5.15 million, with the economy adding 411,000 jobs.

The improved jobs outlook should provide a boost to conservative Prime Minister Mariano Rajoy as he prepares for what promises to be a hard-fought re-election campaign this year. His embrace of fiscal austerity and policies to make it cheaper to hire and lay off workers have made him a favorite with Europe’s leaders, even while costing his government support at home.

“We can now say something that was unthinkable just a few years back: that we have gone from being responsible for half of the job losses in the European Union to creating half of new jobs in the EU,” Mr. Rajoy said.

For much of the early stages of the European economic crisis, Spain led the EU in unemployment, with Greece’s rate becoming the highest only in mid-2012.

Spain’s government and private-sector economists anticipate that the rate—which peaked at 26.9% in the first quarter of 2014—may drop below 20% next year. Meanwhile, Greece’s unemployment rate was at 25.6% as of March 31 and is unlikely to drop this year given a renewed recession there.

Spain benefited from high tourism and brisk economic growth in the second quarter, traditionally the strongest for Spain’s labor market. Spain’s Public Works ministry said on Wednesday that foreign arrivals were up 4.2% in January-June, boosted by political and economic troubles in competing Mediterranean destinations from Tunis to Greece.

Spain’s economy grew at an annual pace of around 4% in the second quarter, driven by low energy prices and borrowing costs.

Economists in Spain are debating about how much of the better jobs performance is attributable to Mr. Rajoy’s labor reforms, which went into effect in 2012. In a widely discussed analysis released this month, experts at Madrid’s Fedea think tank said that the labor policies, often cited by German politicians chastising Athens for the lack of reforms, may have had no effect on Spain’s job creation numbers at all.

“What we see is that, for each added 1% of GDP, there’s a 1.5% rise in work-hours,” said Juan Antolín-Díaz, the report’s lead author and an economist at Fulcrum Asset Management. “That ratio hasn’t changed after the labor reform.”

However, experts in labor litigation and corporate executives say that the labor overhaul has had more subtle effects by making unions more amenable to compromises in workplace policies. Unions have had to become more flexible about allowing staff to change shifts or be moved across company departments, which for more job creation and corporate expansion, executives says.

María Carceller, chief executive of Rodilla, a company that operates more than 100 restaurants across Spain, said that she’s seen evidence of the reform’s positive effect since she took over in 2012.

The company posted a 10% rise in first-half revenue, and Ms. Carceller said that she plans to add close to 150 new jobs this year to the current 850 staff.

This accelerated expansion, she adds, is possible partly because Rodilla unions earlier this year signed a collective bargaining deal under the new labor rules, tying wage increases to productivity rises—the first time that has happened in Rodilla’s 76-year history.

“The company is now all about meeting targets, at every level,” Ms. Carceller said. “The whole reinvention of this company started with the labor reform.”