Abstract: Introduction: Brain fog is a phenomenon experienced by persons with pain, described as a mental cloudiness associated with cognitive challenges (e.g., remembering information) that may result in reduced participation. Canadian Veterans are twice as likely as civilians to experience chronic pain and, consequently, brain fog. The experience of brain fog is also described by people with other conditions (e.g., traumatic stress) that are common among Veterans with chronic pain. The impact of brain fog from chronic pain among Veterans has not been qualitatively described. The purpose of this study was to describe the phenomenon and impacts of brain fog among Veterans with chronic pain. Methods: The study used a qualitative descriptive approach, guided by a constructivist theoretical lens. Focus groups were conducted to generate data, and verbatim transcripts were analyzed using an inductive content and gender matrix analysis. Results: Twenty-five Veterans (six women, 19 men) across Canada participated in this study. Three descriptive categories were identified: 1) brain fog experiences, 2) reciprocal and linear relationships of the triggers, impacts, and strategies to manage brain fog, and 3) barriers to and solutions for management. The matrix analysis identified gender differences in impacts and management strategies. Discussion: Brain fog was described as a fluctuating experience that could generate reciprocal cognitive and emotional impacts, creating challenges with meaningful engagement and goal achievement. To reduce the burden of this experience and restore quality of life, Veterans emphasized the need for awareness, development of tools to measure brain fog, and modifications to existing interventions.