What is the method name used to start a thread in Java?

The method used to start a Java thread is start().

Calling start() asks the JVM to schedule a new thread of execution. That new thread eventually runs the Thread object’s run() method. The distinction matters: calling run() directly is an ordinary method call that executes on the current thread, so it does not create concurrent execution.

A common pattern is to place work in a Runnable and pass it to a Thread constructor, then invoke start(). A class can also extend Thread and override run(), although composition with Runnable is generally more flexible. Once a Thread has been started, Java does not allow the same Thread object to be started again; attempting it throws IllegalThreadStateException.

The method’s name describes the lifecycle transition, not the task itself. run() contains or dispatches the work, while start() establishes the separate execution path. Modern Java also supports virtual threads, introduced in Java 21, but starting one still follows the same conceptual separation between scheduling a thread and running its task.