Psychology is the science of behaviour and artificial intelligence is the science of building machines that can perform tasks requiring human intelligence such as reasoning, data processing, decision making, pattern recognition and translation of the language. AI has emerged as a transformative force in psychology. It has the potential to revolutionize the science of psychology, its practice and even its education. While humans use their experience to acquire knowledge, AI acquires knowledge through algorithms by processing vast amounts of data and identifying patterns, which is known as machine learning. Just as psychology can help predict, recognize objects, understand natural language, etc., AI too does the same through machine learning (ML). One important area in which psychology and AI work together is ‘language’. The idea that machines can use language led to the invention of the first chatbot, named ELIZA. Then onwards it is seen that AI applied to language has led to recognizing and translating handwriting, speech recognition, etc., so perfectly that application of AI to complex field like recognizing psychological features from mere speech, has become possible. This chapter presents application of AI in different selected fields of psychology in which AI is effectively used. AI and psychological research go hand in hand, with AI as an engineering discipline devises reliable, accurate, efficient and flexible machines that can perform operations that humans alone have been capable of. Just as psychology can help predict, recognize objects, understand natural language, etc., AI too does the same through machine learning (ML). AI and psychological research go hand in hand. The combination of psychology and AI (computer science) results in useful measures of quality for predicting psychological outcomes, which in turn could affect improvement in both principles of intelligent behaviour as well as their respective computer applications. The chapter ends with stating that AI, which has made inroads in almost all disciplines including social sciences, when applied to psychology, its role combined with that of AI helps transform the world of psychology and may be more appropriate to label the combination of the two fields as, ‘AI of Psychology and Psychology of AI’.