Objective: To determine the feasibility of an online cognitive behavioral therapy for insomnia (CBT-I) in bereaved older adults. Participants: The study participants include adults aged 55 and older (N = 30) that lost a loved one within the past five years and are currently experiencing symptoms of insomnia. Methods: This study used an experimental design and was guided by the Transitions Theory developed by Meleis. Descriptive statistics and t-tests were used to measure changes within and between groups. Experimental arm had the CBT-I online treatment and the control arm had attention controlled online tasks. Intervention fidelity was measured. Results: The online CBT-I intervention is a feasible intervention for bereaved older adults with insomnia. High retention rates were shown in both groups, and both groups’ insomnia and mood symptoms improved at post- study measurement. There were no statistically significant differences seen in any measure between groups. Conclusions: Transitions in older adult life includes loss of friends and family as well as development of sleep issues. The Transitions Theory is useful for informing the design of behavioral interventions in this older population. Further research is needed to understand how sleep can be improved by cost effective online interventions that might not include solely CBT-I.