This research aims to evaluate the best locations for tidal and wave energy conversion in Iranian seas. First, relevant technologies were reviewed. Then the application of these technologies in Iranian seas was studied focusing on the most important parameters of wave heights, wave period, tidal velocity, water depth, and shore condition. The results show that power of 15.8 MW can be extracted by constructing a tidal dam with a tidal level of 3.75 m in Khowr-e Doragh. In the case of tidal kinetic energy, the Qeshm Channel with an average tidal current velocity of 1.5 m/s and a power flux of 13 MW at its narrowest point is suitable for extracting tidal current energy in Iran. For wave energy absorption, three different sites were investigated: Amirabad in the Caspian Sea, Asaluyeh port, and Faroor Island in the Persian Gulf. The results revealed that a heaving-buoy array was most compatible with the wave condition of these sites for energy extraction. However, a U-oscillating water column (OWC) wave converter was appropriate for wave energy extraction at the Faroor site, due to its shoreline and more extreme wave climate.