Elon Musk has not been officially granted "top security clearance" in the U.S. as of public records. However, there have been instances where he interacted with government agencies that require security clearance. For example:
SpaceX Contracts and Government Work: SpaceX, Musk's aerospace company, has been awarded contracts with NASA, the U.S. military, and other federal agencies. To fulfill these contracts, SpaceX and its employees, including Musk, may have been required to adhere to security protocols and clearance standards, especially for classified missions like launching military satellites or developing space technologies used by the U.S. government.
National Security Space Launch (NSSL) Contracts: Musk's company SpaceX has been involved in national security-related projects and has worked with entities like the U.S. Air Force and other defense branches. This could imply Musk's involvement with information that may require some form of security vetting, although specifics about any individual security clearance haven't been disclosed.
However, the exact level of security clearance Musk has, if any, has not been officially confirmed by public sources. It is also worth noting that security clearance is typically tied to individuals who handle sensitive or classified information in government or defense-related positions. Musk, as a private individual, would only be granted such clearance if it were relevant to his business dealings with government entities.