AimPatient‐reported outcomes (PROs) hold significant potential in guiding clinical decision making, yet their utilization in periodontal trials has been limited. This systematic review aimed to critically synthesize and analyse qualitative studies that evaluated the knowledge and impact of periodontitis and its treatment on patients' lives, as well as their motivations, expectations and experiences in seeking treatment.Materials and MethodsSix databases were searched up to March 2024 for qualitative studies on periodontitis patients. Studies were quality‐assessed using the JBI Critical Appraisal and ConQual tools. Two authors independently extracted the findings, with discrepancies resolved by a third reviewer.ResultsThirteen studies from 2006 to 2023 across four continents, involving 215 participants, identified five themes related to periodontitis: (i) knowledge about periodontitis and its treatment; (ii) impact of periodontitis on patients' lives; (iii) motivation and treatment expectations; (iv) obstacles to treatment; and (v) treatment impact on patients' lives.ConclusionSignificant physical and psychosocial impacts of periodontitis on patients' lives were identified, along with critical gaps in knowledge and awareness, emphasizing the important role of dentists in patient education. Specific PROs for use in validated instruments tailored to periodontitis were identified. These results can enhance patient‐centred care by guiding future studies in accurately assessing patient perspectives on their condition and treatment.