Background: Despite the COVID-19 vaccine being proven safe and effective against the novel SARS CoV-2 virus, it has been challenging to bring the socio-economically disadvantaged urban slum dwellers of Bangladesh under vaccination coverage. Therefore, this study was conducted with the aim to determine the extent and determinants of COVID-19 vaccine acceptance among the urban slum-dwellers of Bangladesh. Methodology: This cross-sectional study was conducted in seven urban slums of Dhaka city (capital of Bangladesh) in July 2021 with 318 participants via face-to-face interview using a semi-structured questionnaire. The association of various socio-demographic, economic, religious, knowledge, and health service-related factors with the COVID-19 vaccine acceptance was analyzed using a multivariate regression method. Result: The majority of the participants were day-laborers (32.02%), and 58.49% were male. Only 8% of the household of slum dwellers earned above 25000 Tk, and 35.85% received no education. Almost 40% of the participants had elderly (>60 years old) family members in their households, and only 16 participants received a dose of COVID-19 vaccination at the study. Among the 302 participants who had not received the vaccination, 62.58% of participants stated their willingness to receive the COVID-19 vaccine in the future. The majority (58%) preferred local vaccine camps to receive vaccines rather than going to the designated healthcare facilities. The results from the multivariate logistic regression revealed that the participants who were 60 years or older (aOR: 1.78, CI: 0.56-5.68), had adequate knowledge regarding COVID-19 symptoms (aOR: 4.49, CI: 2.14 ��� 9.39), had comorbid patients in their households (aOR: 2.56, CI: 1.13 ��� 5.83), had no religious misconceptions ((aOR:6.38, CI: 3.31 - 12.29), and did not doubt the safety of the vaccine (aOR: 2.56, CI: 1.00 ��� 6.57) showed higher odds of COVID-19 vaccine acceptance. Conclusion: Appropriate measures should be taken to enhance the knowledge and dispel the misconceptions of the urban slum-dwellers regarding the COVID-19 vaccine. Also, local vaccination camps should be set up in the slum areas to increase the vaccination coverage among the slum-dwellers to bring them under vaccination coverage as soon as possible.