Sexual and gender minority and racialized populations experienced heightened vulnerability during the Covid-19 pandemic. Marginalization due to structural homophobia, transphobia and racism, and resulting adverse social determinants of health that contribute to health disparities among these populations, were exacerbated by the Covid-19 pandemic and public health measures to control it. We developed and tested a tailored online intervention (#SafeHandsSafeHearts) to support racialized lesbian, gay, bisexual, transgender, queer, and other persons outside of heteronormative and cisgender identities (LGBTQ+) in Toronto, Canada during the pandemic. We used a quasi-experimental pre-test post-test design to evaluate the effectiveness of a 3-session, peer-delivered eHealth intervention in reducing psychological distress and increasing Covid-19 knowledge and protective behaviors. Individuals ≥18-years-old, resident in Toronto, and self-identified as sexual or gender minority were recruited online. Depressive and anxiety symptoms, and Covid-19 knowledge and protective behaviors were assessed at baseline, 2-weeks postintervention, and 2-months follow-up. We used generalized estimating equations and zero-truncated Poisson models to evaluate the effectiveness of the intervention on the four primary outcomes. From March to November 2021, 202 participants (median age, 27 years [Interquartile range: 23-32]) were enrolled in #SafeHandsSafeHearts. Over half (54.5%, n = 110) identified as cisgender lesbian or bisexual women or women who have sex with women, 26.2% (n = 53) cisgender gay or bisexual men or men who have sex with men, and 19.3% (n = 39) transgender or nonbinary individuals. The majority (75.7%, n = 143) were Black and other racialized individuals. The intervention led to statistically significant reductions in the prevalence of clinically significant depressive (25.4% reduction, p < .01) and anxiety symptoms (16.6% reduction, p < .05), and increases in Covid-19 protective behaviors (4.9% increase, p < .05), from baseline to postintervention. We demonstrated the effectiveness of a brief, peer-delivered eHealth intervention for racialized LGBTQ+ communities in reducing psychological distress and increasing protective behaviors amid the Covid-19 pandemic. Implementation through community-based organizations by trained peer counselors supports feasibility, acceptability, and the importance of engaging racialized LGBTQ+ communities in pandemic response preparedness. This trial is registered with ClinicalTrials.gov, number NCT04870723.