Leaders of rich nations are deeply unpopular. That spells trouble ahead.

Rarely have the rich world’s political leaders been so widely disliked. No leader of an industrialized country other than tiny Switzerland has a positive rating, according to a survey of some 25 democracies by pollster Morning Consult. Ruling parties that went to the polls this year largely got a drubbing, including in the U.S. and U.K.

President Biden has a 37% approval rating. Canada’s Prime Minister Justin Trudeau has 26% approval, while France’s Emmanuel Macron sits at 19% and German Chancellor Olaf Scholz at 18%, according to Morning Consult. Donald Trump’s popularity has been rising since he won the November election, but he still may start his term with a negative net rating, and he was the only president in modern history to start below 50% during his first term.

Voters in industrialized nations are anxious and angry after years of uncertainty caused by the pandemic, war in Europe, high inflation, stagnant real wages and surging immigration. Leaders are struggling to respond, constrained by tepid economic growth, higher borrowing costs and ballooning deficits that mean they are increasingly offering voters tough choices and trade-offs.

It’s a message many voters don’t want to hear, setting the stage for an era of increasingly fractious politics as parties squabble over how to share an economic pie that, with the notable exception of the U.S., isn’t growing. In European countries, it also threatens a kind of political doom loop, where unpopular leaders, often trying to hold together disparate coalition governments, struggle to pass meaningful legislation, preventing them from solving the problems voters elected them to fix in the first place.

France’s government collapsed last week for the first time since 1962 after a fight over budget cuts under Macron. Shortly before, Germany’s fractious coalition government collapsed over disagreements on economic policy, triggering a vote in February that spells likely defeat for Scholz. South Korea’s unpopular president, Yoon Suk Yeol, narrowly avoided impeachment over his short-lived imposition of martial law, which also came amid a budget dispute.

The upshot: Brace yourself for more political turbulence. This dysfunction is creating fertile ground for opposition parties, populists and antiestablishment politicians, from Trump in the U.S. to the far left and far right in Europe. And aided by social media, political cycles are going into overdrive. In the U.S., the incumbent party has now lost three consecutive elections for the first time since the 1890s.

Even new leaders aren’t getting much of a honeymoon. U.K. Prime Minister Keir Starmer, who ousted the unpopular Rishi Sunak when he won an election in July, has an approval rating of just 30% compared with 59% disapproval—just five months into the job. His ratings took a hit after his Labour government’s first budget hiked taxes to try to plug a funding gap.

This doesn’t bode well for liberal democracies, said Seema Shah, who assesses elections at the International Institute for Democracy and Electoral Assistance, an intergovernmental organization. “People are dissatisfied with the quality of their life, and the institutions they look to for help are weak," she said.

In a year when half the world’s population had a chance to vote, the results show the electorate are angrier in the rich world compared with developing countries, where leaders are more popular—or at least less unpopular.

Of the 71 national polls held around the world so far this year, around a third resulted in incumbents being voted out of office, according to Shah’s organization.

But turnover was far greater in industrialized countries. In slow-growing Europe, six incumbents were replaced out of the 10 major national parliamentary and presidential elections held so far this year, and virtually every incumbent party saw its vote share fall compared with the last election. Japan’s long-ruling Liberal Democratic Party lost its outright majority and Prime Minister Shigeru Ishiba’s fragile minority government isn’t expected to last through the coming year.

“Being an incumbent in the industrialized world used to be an advantage, but it is increasingly a disadvantage. Most of them lose," said Ruchir Sharma, the head of hedge fund Rockefeller Capital Management’s international business. The average popularity ratings of the seven richest countries’ leaders has been gradually trending down since the pandemic, according to Morning Consult.

In nearly half of the world’s top 35 developed countries, hourly wages, when adjusted for inflation, are below their 2019 level, according to the Organization for Economic Cooperation and Development. Only 24% of respondents in the developed world said they expected to be better off in five years versus 61% in developing countries, according to a 2023 survey by public-relations firm Edelman.

The big exception is the U.S., but the wage growth there has been uneven. Average incomes have risen, but that is largely driven by gains among top earners. Median incomes are slightly down compared with 2019, meaning many Americans aren’t feeling better off. Lack of affordable housing for many younger Americans and Europeans feeds a feeling that the game is rigged against them, Sharma said.

While consumer-sentiment data in richer countries is improving after the recent inflation shock, “it doesn’t seem to have convinced people that their economies are necessarily on a surer footing for the longer run," said Jason McMann, head of political intelligence at Morning Consult. For instance, Spain’s economy rebounded strongly from the pandemic, but its leader Pedro Sanchez has an approval rating of just 32%.

The three most popular global leaders in the Morning Consult survey were all in developing countries, though they all represent antiestablishment movements that had booted out traditional politicians: India’s nationalist Narendra Modi (76% approval), Argentina’s fiery libertarian Javier Milei (66%) and Mexico’s Claudia Sheinbaum (64%). Milei won election a year ago as a political outsider with a vow to take a chain saw to Argentina’s bureaucracy.

Rich countries have a problem that poorer ones don’t: They are aging rapidly, which means their costs for healthcare, pensions and other spending are rising quickly at a time when their economic growth has stagnated, meaning less tax revenue to pay for services. In the past two decades, governments in rich countries have turned to borrowing to plug the gap.

But that has now largely reached its limits. Gross government debt among the G-7 club of rich countries is up from 74% of gross domestic product in 2001 to 124% in 2023. Interest rates on government debt have risen sharply in the past two years. Outside the U.S., most of those governments won’t be able to keep borrowing without causing growing worries among investors about their ability to repay. That means politicians will face far more difficult and politically unpopular choices: raising taxes, cutting spending or both, unless they can make spending more efficient or boost productivity.

“Trump is maybe the only one who can inherit a 7% deficit and possibly expand that, but none of the other leaders can," said Heather Grabbe, a senior fellow at the Bruegel think tank in Brussels. “The fiscal constraints are real. Everyone else has to figure out how to deliver without more money while spending more on defense and the energy transition. It’s a real bind."

Grabbe also said voters in many European countries are still feeling the effects of austerity after the financial crisis of 2007-2008, when many governments had to rein in spending, leading to a deterioration in public services.

There are factors beyond the economy to explain why voters are upset across the rich world. One is a spike in migration, an issue that few politicians on the left and right have managed to successfully address. The U.S. saw a historic rise in illegal border crossings, and Europe has also seen a surge in asylum seekers in recent years.

The immigration issue has helped fuel the rise of the populist right, which has built a stronger foothold in many countries this year. The Austrian far-right Freedom Party came first in September’s election, for the first time in the country’s history. In France, Marine Le Pen’s National Rally performed strongly in the European parliamentary elections. Croatia’s ruling party formed a coalition with far-right nationalists. Currently six European Union countries have parties with right-wing anti-migration agendas in government.

While only a few of these populist right parties have been able to take control of European governments, they have become a destabilizing force in coalition politics, said Sara Hobolt, a politics professor at the London School of Economics. “It is starting to become significant," she said.

Another factor is structural. Growing disillusionment and social media mean younger voters are less loyal than their parents to political parties and back a range of smaller parties with different ideologies. That has created unstable coalitions, like in Germany or France, that cobble together parties with different priorities and make it hard to take far-reaching decisions to foster economic revival.

There is now also an increasing “presidentialization" of leaders, with people endorsing politicians based on their personality rather than their policies, said James Johnson, founder of the pollster JL Partners. So when things go wrong, those individuals are directly blamed and their approval quickly sinks, he said.

One possible solution, said Johnson: a charismatic leader who lays out the tough decisions ahead to voters and convinces them they are worthwhile. “Politicians will have to think differently about how they become popular," he said. “You can’t trick the people."

Write to Max Colchester at Max.Colchester@wsj.com and David Luhnow at david.luhnow@wsj.com