Apply a Meta tag to one page only

by

You have two options. Both involve using a conditional tag. I don’t know which conditional you’ll need to test for, hence the “{something}” placeholder. (If I had to guess, you may use the is_page( $ID ) tag.)

Edit your theme header file.

It’s usually called header.php:

if( is_{something}() ) {
    echo '<meta ......... />';
}

Use the wp_head hook in your functions.php file

function wpse_54694() {
    if( is_{something}() ) {
        echo '<meta ......... />';
    }
}
add_action( 'wp_head', 'wpse_54694' );