Objectives: We aimed to determine the prevalence of HIV-related stigma among people with HIV (PWH) in Switzerland Design: A cross-sectional multicenter study nested within the Swiss HIV Cohort Study (SHCS). Methods: We included adult PWH enrolled in the SHCS, attending follow-up between March 1, 2020, and January 31, 2021. Inability to speak English, French, German, or Italian was the only exclusion criterion. Participants were invited to complete a validated 12-item HIV-stigma questionnaire comprising four stigma subscales (negative self-image, personalized stigma, disclosure concerns, and concerns regarding public attitudes), plus two healthcare-related stigma items. Questionnaire responses were graded using a four-point Likert-type scale, higher scores indicating higher stigma. “Non-applicable,” inferring HIV-status non-disclosure, was possible for personalized stigma; stigma scores from participants answering “non-applicable” to at least one item were analyzed separately. Factors associated with HIV-stigma were identified through multivariable linear models. Results: Of 9643 PWH with a SHCS visit, 5563 participated in the study: 26% were female, 13% Black, and 37% heterosexual; median age was 53 years (interquartile range 44–59); 2067 participants (37%) gave at least one “non-applicable” response. Disclosure concerns had the highest stigma scores and were reported by 4656/5563 (84%). HIV-stigma was reported across all demographic groups. However, being female, Black, and heterosexual were independently associated with higher scores. Higher education and longer follow-up duration were associated with lower scores. Healthcare-related stigma was reported in 37% of participants. Conclusion: HIV-stigma was prevalent across all demographic groups. The association with being female and Black suggests that HIV-stigma accentuates preexisting sex and race inequalities.