The composition of groundwater governs the drinking and irrigation water suitability. A large part of the coastal region of Bangladesh is affected and is responsible for changing the composition of the groundwater. This research attempted to observe the groundwater quality of the Bhola Sadar and Char Fasson upazilas in coastal Bangladesh. Twenty-eight (28) water samples, 27 at depths of 260–430 m (850–1400 ft) and 1 from a crop field, were collected and analyzed. The quality of water samples was determined through the evaluation of odor, color, turbidity, electrical conductivity, pH, total dissolved solids, nitrate (NO₃⁻), ammonium (NH₄⁺), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn) and arsenic (As) ions. An Atomic Absorption Spectrophotometer was used for heavy metal analysis. The outcomes were compared with the drinking water quality of Bangladesh and the World Health Organization. The results showed that the average values of nearly all of the parameters were underneath or within the standard level, representing that the groundwater was appropriate for drinking purposes. The water quality parameters were also compared with the irrigation water quality of Bangladesh and the Food and Agriculture Organization. It was found that the collected samples were also suitable for irrigation. To do this, the soluble sodium percentage, sodium adsorption ratio, magnesium adsorption ratio, Kelley’s ratio, and total hardness were calculated. The novelty of this research is that, despite being in a coastal district, the deep aquifer water of Bhola was appropriate for drinking and irrigation purposes.