Sugar-sweetened beverage (SSB) consumption in early childhood is a public health concern. Adequate hydration in early childhood is also important. Healthy Eating Research developed a national research agenda to improve beverage consumption patterns among 0- to 5-year-olds. This article focuses on the process used to develop this research agenda. A mixed methods, multi-step process was used to develop the research agenda, including: (i) a scientific advisory committee; (ii) systematic reviews on strategies to reduce SSB consumption and increase water access and consumption; (iii) two stakeholder surveys to first identify and then rank strategies to reduce SSB consumption and increase water access and consumption; (iv) key informant interviews to better understand determinants of beverage consumption and strategies to improve beverage consumption patterns among high-risk groups; (v) an in-person convening with experts; and (vi) developing the final research agenda. This process included research and stakeholders from across the United States. A total of 276 participants completed survey 1 and 182 participants completed survey 2. Key informant interviews were conducted with 12 stakeholders. Thirty experts attended the convening, representing academia, government, and non-profit sectors. Thirteen key issue areas and 59 research questions were developed. Priority topics were beverage consumption recommendations, fruit-flavored drink consumption, interventions tailored to high-risk groups, and family engagement in childcare. This research agenda lays the groundwork for research efforts to improve beverage patterns of young children. The methods used can be a template to develop research agendas for other public health issues.