Background <p>Older populations globally are experiencing a rise in sexually transmitted infections, and those who travel internationally and engage in unsafe sex practices are particularly at risk. International retirement migrants, who live abroad for extended periods each year, pose unique challenges for public health efforts to prevent, track, control, and treat these infections. To date, no research has examined the specific opportunities and challenges for sexually transmitted infection prevention among Canadian international retirement migrants who winter in the United States. This study addresses that gap by drawing on local providers’ and administrators’ perspectives from Yuma, Arizona, a popular winter destination for older Canadian retirees, and exploring opportunities and challenges for sexual health promotion for older mobile populations.</p> Methods <p>Using a qualitative case study approach, we conducted semi-structured interviews with key informants with deeply situated expertise in Yuma (<i>n</i> = 10), including public health and health care providers and senior administrative professionals. Participants shared their insights based on their extensive experience treating or administering care for collectively hundreds of Canadian winter visitors. Interviews were transcribed verbatim, coded using NVivo, and thematically analyzed.</p> Results <p>Opportunities and challenges that emerged were connected to three distinct pathways: system, community, and individual. Opportunities included leveraging telehealth tools and outreach initiatives to increase awareness of sexually transmitted infection prevention, fostering local partnerships to destigmatize sexual health discussions, and promoting awareness and testing for sexually transmitted infections. Challenges included travel insurance limitations and digital literacy issues among Canadian retirees, staff shortages that limited public health outreach, cross-border care coordination challenges, and inadequate education among medical providers to support discussions of sexual health with older adults.</p> Conclusions <p>This analysis highlights multiple significant opportunities and challenges in improving sexually transmitted infection prevention efforts for Canadian older seasonal migrants in Yuma, Arizona. Addressing these barriers and leveraging opportunities to inform sexual health educational outreach into retirement communities is crucial for public health and health system decision-makers to reduce disease spread and the heavy seasonal demand on the local health system.</p>