A research vessel (RV or R/V) is a ship or boat designed, modified, or equipped to carry out research at sea. Research vessels carry out a number of roles. Some of these roles can be combined into a single vessel but others require a dedicated vessel. Due to the demanding nature of the work, research vessels are often constructed around an icebreaker hull, allowing them to operate in polar waters.

Oceanographic research vessels carry out research on the physical, chemical, and biological characteristics of water, the atmosphere, and climate, and to these ends carry equipment for collecting water samples from a range of depths, including the deep seas, as well as equipment for the hydrographic sounding of the seabed, along with numerous other environmental sensors. These vessels often also carry scientific divers[4] and unmanned underwater vehicles. Since the requirements of both oceanographic and hydrographic research are very different from those of fisheries research, these boats often fulfill dual roles