The default WordPress Theme template for listing comments and pingbacks displays comments from oldest to newest. To list the WordPress Post comments in reverse chronological order, you can make this simple change in your comments.php template file.
Locate a line which looks like the following:
<?php foreach ($comments as $comment) : ?>
and wrap around the $comments variable, array_reverse():
<?php foreach (array_reverse($comments) as $comment) : ?>
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