Sentiment analysis is the process of identifying people's point of view and its impact on them. It determines whether apiece of writing is positive, negative, or neutral. Now-a-days one of the most common tool for sharing opinion is the Internet. This opinion may be different moods of people or reviews about products and so on. People share their views on social-networking websites which proves to be an important source of information. Twitter is one of the most popular social networking website where people post their opinion in the form of tweets. The proposed onto-fuzzy logic system provides a new approach where it uses hash tag level sentiment classification of tweets along with fuzzy logic. Sentiment analysis done with fuzzy logic will help any person to take effective decision according to the product or service of their interest.