The next months will be critical to help those hit hardest by COVID-19 and ensure that countries resume reducing poverty and address the needs of people at risk of being left behind. IISD and partners – the Leave No One Behind Partnership – are launching a series of articles to explore this challenge. Commentary will delve into three broad themes: current knowledge of COVID-19 and its long-term impacts; green shoots and measures that work; and the promise and risk of data for Leaving No One Behind.