Its World Happiness Day, otherwise known as International Day of Happiness, but if youre not feeling the love, youre not alone. Many Americans arent that happy, according to the World Happiness Report 2025, which ranks happiness across nations. In fact, America doesnt even crack the top 20 happiest countries in the world, and instead now sits at No. 24earning its lowest ranking yet. (Spoiler alert: Finland once again is the happiest.)The report, which asked people from 140 countries to evaluate their life, looked at six major factors to predict happiness: GDP per capita, social support, healthy life expectancy, freedom, generosity, and perceptions of corruption. Each person ranked their own happiness over the past three years from 2022 to 2024.While all those factors are important, the key to happiness is often attributed to Harvard Universitys landmark 85-year Study of Adult Development, which discovered that close relationships are the strongest predictor of happinessthroughout our lives.The young and the hopelessPerhaps one reason for Americas plummeting levels of happiness can be understood through the eyes of Gen Z, who are currently experiencing an epidemic oflonelinessand isolation (as are many Americans, but not to the same extent). The report found young people worldwide were increasingly lonely, with 19% reporting in 2023 that they have no one to count on for social support, a 39% increase from 2006.The decline in the U.S. in 2024 was at least partly attributable to Americans younger than age 30 feeling worse about their lives, Ilana Ron-Levey, managing director at Gallup, part of the World Happiness Report 2025, toldCNN. Todays young people report feeling less supported by friends and family, less free to make life choices and less optimistic about their living standards.It also found that in the United States and parts of Europe, lower levels of both happiness and trust have greatly contributed to more polarization along political lines.The silver lining? One positive finding was that people often underestimate other peoples kindness; that is to say, people are often kinder than we think, and doing nice things for others actually makes you happier.What are the worlds happiest countries?Here are 2025s top 20 happiest countries in the world.FinlandDenmarkIcelandSwedenNetherlandsCosta RicaNorwayIsraelLuxembourgMexicoAustraliaNew ZealandSwitzerlandBelgiumIrelandLithuaniaAustriaCanadaSloveniaCzech RepublicThe five countries where people were most unhappy? At the bottom of the list: Afghanistan, once again the last-place holder; Sierra Leone, Lebanon, Malawi, and Zimbabwe.The report is the result of a partnership between Gallup, the Oxford Wellbeing Research Centre, the U.N. Sustainable Development Solutions Network, and an editorial board.