Bangladesh, being the world's most climate-vulnerable country, is affected by plenty of climate-related hazards every year, mostly along its south-western coast. As a consequence, many people relocated from these regions' worst-affected neighborhoods to Khulna city, and began to live as slum dwellers. They faced a variety of issues in these informal settlements, particularly regarding water, sanitation, and hygiene (WASH) facilities and livelihood options, but no research has been conducted in Bangladesh. With an emphasis on WASH services and livelihood prospects, this study therefore aimed to provide a comprehensive understanding of the challenges/hardships and needs of climate migrants living in urban slums in both general and COVID-19 contexts. Qualitative methods were applied to collect data from the climate migrants of slums in five wards (3, 12, 17, 21, and 30) of the Khulna City Corporation. Nine focus group discussions and four key informant interviews were conducted to collect the data from primary (community people) and secondary (local government and non-government and community-based organizations officials) stakeholders. The thematic analysis was used to analyze the data. The findings revealed that climate migrants experienced significant water scarcity, insufficient drainage systems, a lack of toilets, tube wells, and bathing facilities, inadequate hygiene management, a lack of core skills required for urban jobs, low payment, and an income shortage. Similarly, sustainable drinking water sources, sanitary toilets with WASH blocks, personal hygiene materials and awareness building, skill development for diverse livelihood opportunities, and income-generating capacity development were their top priorities. Overall, the findings of this study provided a holistic overview of the challenges/hardships and needs of climate migrants in urban slums regarding WASH services and livelihood opportunities. The authorities should intervene and develop policy initiatives to alleviate the hardships and meet the needs of climate migrants.