Rural–urban migrants play an important role in China’s urban food economy. To investigate the contribution of migrants in urban food systems, this chapter analyses several datasets collected by the Hungry Cities Partnership in Nanjing over the past seven years, including a city-wide migrant farmer survey, a food vendor survey, a supermarket survey and a household food security survey. The chapter shows that rural–urban migrants are extensively involved in food production, wholesaling, and retailing and as supermarket employees. Working as migrant farmers and migrant vendors, rural–urban migrants contribute significantly to urban food security, improving both food availability and accessibility. The chapter also unveils the challenges facing migrants, including food insecurity, food retailing challenges, and how the daily operation of migrant food vendors was affected by COVID-19.