Depression, anxiety, and stress have surged worldwide, including in Bangladesh during the COVID-19 pandemic. This study aimed to assess the mental health condition of the Bangladeshi population during this pandemic. A cross-sectional study was carried out online between Feb 17, 2021, and Apr 8, 2021, during the lockdown period in Bangladesh with structured questions of the DASS-21 (Depression Anxiety Stress Scales-21), and about 310 responses were collected for the study purpose. One-way ANOVA and statistical analysis were performed by STATA-13 to determine the statistical significance. Depression was found to be significantly associated (p < 0.05) with both level of education (higher level observed among postgraduates) and previous psychological intervention (higher rate of being exposed to psychiatrists earlier). Comparing normal, mild, moderate and severe levels, the most common level of depression was moderate (28.06%) among the respondents, along with highly severe anxiety (22.26%) and moderate stress (18.39%). Participant's living area was significantly associated with depression (p = 0.033) and anxiety (p = 0.014), with individuals residing in urban areas exhibiting higher rates. Despite their adverse mental health status during the pandemic, only 36 out of 310 (12%) participants visited psychologists or psychiatrists. There remains substantial stigma around seeking formal mental health treatment in Bangladesh, such as low compliance rates even for talk therapy. Government organizations and NGOs should raise awareness among the public by conducting community-level campaigns, offering state-level insurance, initiating peer support programs, and using digital space to familiarize people with mental health issues.