fontStyle: String

Sets the fontStyle of Chart Title. fontStyle can be set to one of the below options.

Default: “normal”
Options: “normal”, “italic” , “oblique”

 var  chart =  new  CanvasJS.Chart("container",
 {
  .
  .
  title:{
   fontStyle: "italic",
  },
  .
  .
 });
chart.render();