Rising global demand for vegetable oil during the last few decades has led to a drastic increase in the land area under oil palm. Especially in Southeast Asia, the oil palm boom has contributed to economic growth, but it has also spurred criticism about negative environmental and social effects. Here, we discuss palm oil production and consumption trends and review environmental, economic, and social consequences in different parts of the world. The oil palm expansion has contributed to tropical deforestation and associated losses in biodiversity and ecosystem functions. Simultaneously, it has increased incomes, generated employment, and reduced poverty among farm and nonfarm households. Around 50% of the worldwide oil palm land is managed by smallholders. Sustainability trade-offs between preserving global public environmental goods and private economic benefits need to be reduced. We discuss policy implications related to productivity growth, rainforest protection, mosaic landscapes, land property rights, sustainability certification, and smallholder inclusion, among others. Expected final online publication date for the Annual Review of Resource Economics, Volume 12 is October 5, 2020. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.