Population explosion has caused serious environmental and energy-related problems that have increased the interest of researchers to develop new nontoxic, inexpensive, stable, and efficient materials to address these environment and energy-related issues. Among the different efforts, the development of photocatalysts is considered as an important way to utilise the sustainable solar energy for environment remediation and energy purposes. Presently, several hundred photocatalysts have been synthesized. Among them, alkali niobates and tantalates represent an important class of photocatalysts, because of their nontoxicity, structural flexibility, and simplicity. This review summarizes recent developments in synthetic strategies of alkali niobate and tantalates, their important application as photocatalysts for environment remediation and energy applications, and efforts being made to modify their physicochemical properties and extend their efficiencies by tuning different reaction conditions. The purpose of this Review is to discuss methods to regulate the efficiencies of these materials and future challenges faced for practical applications.