INTRODUCTION: Poor sleep is ubiquitous in skilled nursing facilities (SNFs) and is associated with a myriad of negative symptoms. Non-pharmacological interventions can improve sleep, yet sustainability has not been demonstrated. The Improving Sleep Using Mentored Behavioral and Environmental Restructuring (SLUMBER) trial will test whether a staff mentoring approach to address resident sleep issues positively impacts sleep quality and whether improved sleep benefits mood, cognitive performance, and activity engagement for residents living in SNFs. INTERVENTION: This is a four-year hybrid type I effectiveness/implementation randomized stepped-wedge trial using a comprehensive sleep improvement program conducted in three urban SNFs. METHODS: We will provide SNF staff with sleep promotion strategies over a four-month intervention. Staff will have access to in-person workshops, webinars, weekly sleep pearls via text messaging, environmental data, and expert program mentors. We will consent residents for data collection (at baseline, end of intervention, and three- and six-months post-intervention) including resident observations, questionnaires, and wrist actigraphy (to objectively measure sleep). We will also use selected Minimum Data Set 3.0 (MDS) measures. CONCLUSION: SLUMBER uses a unique strategy to iteratively improve sleep interventions through SNF staff buy-in, expert mentoring, and technological supports within a quality improvement framework. As a stepped-wedge trial, the initial SNF units provide opportunities for program improvement in subsequent units, accounting for variation across resident populations at different sites. Protocol limitations include strategies which may require substantial customization for greater spread. A comprehensive staff training program that addresses both sleep quality and related symptoms has the opportunity for considerable dissemination. TRIAL REGISTRATION: USGOV Clinical Trials ID: NCT03327324.