Disclosing personal feelings could reduce stress during a difficult time, such as the COVID‐19 pandemic. The current study examined the linear and curvilinear relationships between willingness to self‐disclose to a romantic partner and COVID stress. Participants completed questionnaires online regarding willingness to self‐disclose, COVID stress, relationship factors, and self‐esteem. Results showed a marginally significant inverted U‐shaped curvilinear relationship between willingness to self‐disclose and COVID stress, suggesting the trend that individuals who were willing to self‐disclose at a low or high level had lower COVID stress compared to individuals who were willing to self‐disclose at a medium level. This relationship was mediated by commitment and self‐esteem. Future research could examine the impact of self‐disclosure on COVID stress using an experimental or longitudinal design. [ABSTRACT FROM AUTHOR]