Nipah virus (NiV) is a bat-borne pandemic-potential zoonotic virus causing fatal encephalitis outbreaks with >70% mortality. We investigated five suspected NiV outbreaks in Bangladesh between 2021 and 2022 to identify the source, identify behavioral risk practices, and detect and characterize the NiV. We collected epidemiological and ecological data from outbreak communities. We captured 60 Pteropus medius bats per outbreak event and environmental pool urine samples (N = 314) from seven bat roosts within a 10km radius of the outbreak's epicenter. The bat samples were tested for NiV by qRT-PCR and consensus PCR assay targeting rdrp genes of paramyxovirus (PMV) to detect known and novel PMV. We screened bat serums for NiV and related henipavirus antibodies using a multiplex Luminex assay. We detected five NiV cases spillover in humans, with 60% (3/5) case fatalities. We detected NiV in 0.45% (1/224) of bat saliva samples. Additionally, the seropositivity of NiV was 15.2% (34, CI: 10.74%–20.56) in bat samples. The phylogenetic analysis revealed that NiV sequences originating from Bangladesh were segregated into two distinct clades, whereas current outbreak bat NiV sequences were found to cluster with clade 2. Furthermore, we detected two novel henipa-like paramyxoviruses in bat samples taken during outbreak investigations. The behavioral investigation showed that all cases had a history of drinking contaminated raw date palm sap (RDPS) within 14 days prior to the onset of symptoms. In the outbreak communities, the participants had the habit of drinking RDPS 73.1% (CI: 67.04%–78.51%) and eating bat-bitten fruits 17.96% (CI: 13.36%–23.35%). The Generalized Linear Model (GLM) revealed associations between RDPS consumption and participants' occupation, community RDPS harvesting practices, and participant ownership of date palm trees. We recommend stringent One Health surveillance and awareness campaigns in high-risk communities to reduce human-bat interactions and minimize spillover of the bat-borne pathogen to humans and domestic animals.