Background: There is a lack of research that has focused on ADHD in people with cystic fibrosis (pwCF). Given ADHD is associated with executive functioning impairments, exploring ADHD in the context of living with CF is of great importance. The purpose of the current systematic review was to examine ADHD in pwCF across the lifespan in terms of its prevalence, its impact on various health outcomes, and treatments for managing ADHD. Methods: This systematic review followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles reporting studies of any design that focused on ADHD in pwCF were included. Studies were excluded if they did not meet this criterion and if they were written in languages other than English. PsycINFO, MEDLINE, EMBASE, and CINAHL databases were searched. Search items were based on three concepts: 1) terms related to CF, 2) terms related to ADHD, and 3) terms related to age. Results: Ten studies were included in this systematic review. Reported prevalence rates of ADHD in people with CF ranged from 5.26% to 21.9%. The reported relationships between ADHD in pwCF and other health outcomes is also inconsistent. In terms of treatment considerations, pharmacological interventions and behavioural strategies for managing ADHD in the context of living with CF have been reported as being successful. Conclusions: The presence of ADHD in pwCF should be evaluated when symptoms are impacting treatment adherence and health outcomes. Additional research is needed to further explore ADHD in the CF population and health variables that may be associated with CF prognosis.