Who posted Twitter’s first public tweet?

Jack Dorsey posted Twitter’s first public tweet.

Dorsey published the message on March 21, 2006, while the service was still being developed at Odeo, a podcasting company in San Francisco. The short post read, “just setting up my twttr,” using the project’s original shortened name.

The post is widely treated as Twitter’s first tweet because it was the first message sent on the newly created service. It was not a promotional announcement or a later celebrity post; it was a simple status update that documented the platform’s early testing phase.

People sometimes confuse the first tweet with the first tweet sent from space or the first tweet by a company account. Those were much later milestones. Dorsey’s 2006 message is significant because it marks the beginning of Twitter’s public posting history.