Set the location of the tool tip such that its nw corner coincides with the bottom center of the button
import java.awt.Point; import java.awt.event.MouseEvent; import javax.swing.JButton; public class Main { public static void main(String[] argv) throws Exception { JButton button = new JButton("My Button") { public Point getToolTipLocation(MouseEvent event) { return new Point(getWidth() / 2, getHeight()); } }; } }