Barring the CSS solution. The fastest possible way is to hide it immediatly with a script.
<div id="hideme"></div>
<script type="text/javascript">
$("#hideme").hide();
</script>
In this case I would recommend the CSS solution by Vega. But if you need something more complex (like an animation) you can use this approach.
This has some complications (see comments below). If you want this piece of script to really run as fast as possible you can't use jQuery, use native JS only and defer loading of all other scripts.