The opposite of being convinced of something is being uncertain or unconvinced. Doubtful and skeptical are antonyms for "being convinced of" as they express a lack of belief or trust in something. Uncertainty implies a lack of conviction or confidence in a particular idea, while hesitancy suggests a reluctance to accept it outright. Disbelief and suspicion are other antonyms that signify a complete rejection or mistrust of a proposition. In some cases, indifference can also be considered an antonym if there is no interest or emotion invested in the topic being discussed. Ultimately, being convinced of something is the opposite of having doubts, skepticism, or disbelief.