Learning is a cognitive process. It is one of the most important mental functions of human, animals and artificial cognitive systems. It relies on the acquisition of different types of knowledge supported by perceived information. Strategies are ‘the secret algorithms of learning’. The term ‘strategy’ is used to indicate a level above that of skills: strategies are the executive processes which choose, co-ordinate and apply skills. Understanding the strategies of learning and gaining self-knowledge helps us to control these processes and do better. Learning strategies is a technique that assists in the acquisition, manipulation, integration, storage and retrieval of the studied content. This study aims to find the relationship between Learning Strategies and Academic Achievement of the Higher Secondary School Students. By using normative method a sample of 300 Higher Secondary School Students studying from 6 schools in and around Krishnagiri District of Tamil Nadu were randomly selected. SMALSI, a four point scale developed by Stroud and Reynolds (2006) was used for data collection. It consists of 7 dimensions and 52 questions. The collected data were put in to statistical treatment and the results showed that there was significant highly positive correlation (r= 0.739) between the Learning Strategies and Academic Achievement. Hence sound Learning Strategies are important for every learner since it helps them achieve more in their academics.