For many vulnerable older adults, food access was disrupted during the COVID-19 pandemic. In Hawai'i, the Kūpuna (the Hawaiian word for elders) Food Security Coalition (KFSC) was formed in March 2020 to address this challenge, leveraging local and federal funding support. This case study presents information on coalition formation and success in addressing this emergency, as well as evaluation data on coalition functioning as assessed by the Collective Impact (CI) framework. Coalition functioning was assessed across the five CI conditions: common agenda, shared measurement, mutually reinforcing activities, continuous communication, and backbone support. Case study data were available from interview and learning circle transcripts, survey findings, and other program documents. Between March and December 2020, the KFSC coordinated efforts of 46 organizations to serve approximately 1.2 million meals to 8300 vulnerable seniors in Honolulu County. Within the first 9 months of existence, the coalition's measurement system and the common agenda conditions showed advanced maturity, while the other conditions demonstrated moderate maturity levels. Despite challenging leadership transitions, the coalition was successful in helping increase food access and then pivoting in 2021 to promote kūpuna vaccinations, and the coalition continues to meet regularly to address issues of concern to vulnerable older adults. This study provides evidence-based guidance for communities seeking to establish public/non-profit partnerships for emergency food response for older adults, demonstrating how structured coalition approaches can effectively mobilize and coordinate multi-stakeholder efforts during and beyond crises.