Source credibility is multifaceted in social sciences. In marketing and crisis communication, source credibility leads to fact-based positive behavior and message adherence. The believability of information can be indubitable by the credibility of its source. If the source of an organization's information is not trustworthy, it can lead to the spread of false information, also known as infodemic. It is not easy to keep someone's attention for a long time, but some leaders and speakers manage to do it efficiently. The key to their success is source credibility (SC) which is determined by how the public perceives them. In crisis/marketing communication SC is very useful. Crisis communication from a trustworthy source builds public trust, promotes effective crisis response strategies, and safeguards reputation. This paper explains the applicability and how important it is to have source credibility in public speaking, advertisements, politics, religions, crisis communication, media communication, and organizational reputation. Fake news on social media during crises has damaged reputations and caused harm. Organizational information source credibility (ISC) is one salient