Informal settlements in cities in low- and middle-income countries concentrate populations at greater risk of climate change impacts. Community- and city-government-led measures to upgrade settlements are not designed as responses to climate change, but they can enhance resilience to climate-change risks. There is much overlap and complementarity between what informal-settlement upgrading needs and what builds their resilience to climate change; both focus on local risks. Both upgrading and resilience building usually need actions to reduce disaster risk in the wider region. But integrated action is a challenge because responsibility for upgrading and for resilience usually falls under different sectoral agencies.