The growing scale and persistence of humanitarian crises constitute a critical problem for nation-states, aid organizations and crisis-affected people. Many humanitarian responders continue to focus on material aid, providing essential supplies and services during these crises, while other actors restore physical infrastructures. We believe aid efforts are overlooking the pivotal nature of horizontal and vertical ties within and 20 between communities. Using qualitative and quantitative data from Uganda and Nigeria, we show how social capital matters even during the most severe crises. Our interviews and regression analyses of survey data show that deeper reservoirs of bridging social capital associate significantly with the preparedness of individuals displaced by violence in Nigeria, and that bonding and linking social capital correlates with greater resilience for people stressed by food insecurity in Uganda’s Karamoja region. Some concrete policy recommendations emerge for aid agencies and decision-makers that can invest in rebuilding social infrastructure in affected populations.