How to add a "Table of Contents" title in the HTML template

Using the --toc option when generating HTML generates the table of content without the phrase "Table of content". Is there a way to add such phrase before the table of content?

Allow me to point out that it's good that the TOC title is not inserted by default in the standard template, because the exact phrase needed depends on the language of the document! If you want to insert a TOC title into your default template and ever write documents in different languages I'd recommend you to define a variable to set the actual phrase.

In a terminal do

pandoc -D html >$HOME/.pandoc/templates/default.html

or on Windows

pandoc -D html >C:\Documents And Settings\USERNAME\Application Data\pandoc\templates\default.html

Then go to where this 'default.html' is and edit it. Search for $table-of-contents$ and change the lines around it

$if(toc)$
<div id="$idprefix$TOC">
$table-of-contents$
</div>
$endif$

into

$if(toc)$
<div id="$idprefix$TOC">
$if(toctitle)$
<h2 id="$idprefix$toctitle">$toctitle$</h2>
$endif$
$table-of-contents$
</div>
$endif$

or if you want the toc title to always be there, and only sometimes to be in a different language:

$if(toc)$
<div id="$idprefix$TOC">
<h2 id="$idprefix$toctitle">$if(toctitle)$$toctitle$$else$Table of Contents$endif$</h2>
$table-of-contents$
</div>
$endif$

with your most used language's translation of Table of Contents.

Then you can use

pandoc -s --toc -V toctitle:'Table des matières' 

or whatever. This is especially useful if a language uses different forms of the phrase like "Table of contents" or "Contents" depending on the style of the document.

Since we included that id="$idprefix$toctitle" you can also style it with CSS if you want to.