Logic is very important subject and it is impossible to deny its role in the development of modern technology. In modern scenarios, sound decision making is just an impossible without logic and critical thinking. This book is based on the handouts which I had prepared while teaching a course An Introduction to Logic in a university class. The handouts were prepared after consulting different books on the topic. The list of the books which were consulted during the preparation of handouts is given at the end of this book.