HIV-related stigma negatively impacts the health of people who are living with HIV. Stigma may also affect sero-discordant couples where one partner is living with HIV, but the other is not. However, we know little about how HIV-related stigma and couple relationship quality jointly affect depression and anxiety in both the individual and their partner. We analyzed dyadic data from 491 sero-discordant pregnant couples in southwestern Kenya collected during 2019-2022 using Actor-Partner Interdepe