Author Name on Twenty Eleven Theme

Do you mean add bio of author at bottom of posts if so

try this on single.php file just before <?php comments_template() ?>).

<div id="author-bio">
	<h3>About The Author</h3>
	<h4><?php the_author(); ?></h4>
       <?php the_author_description(); ?>
</div><!--end author-bio-->

to have it working the profile of author needs to be updated.

Hi Catalan,

Before making the following change, please make sure you are using a Child Theme so future updates to the theme do not overwrite your changes.

In Twenty Eleven the style sheet contains the following, which hides the author:

.single-author .entry-meta .by-author {
	display: none;
}

To unhide the author name on the front page, in your Child Theme Style Sheet add this:

.single-author .entry-meta .by-author {
	display: inline;
}

Hope this helps!

For some reason the solution does not work on my site. I have changed the line from “display: none” to display: inline;”.
Any idea as to why it does not work?

make sure this all happens in a child theme of Twenty Eleven – do not edit the default theme Twenty Eleven directly.
http://codex.wordpress.org/Child_Themes

you need to copy the relevant section from content-single.php, and enter it into content.php, into the corresponding location.

<?php if ( get_the_author_meta( 'description' ) && ( ! function_exists( 'is_multi_author' ) || is_multi_author() ) ) : // If a user has filled out their description and this is a multi-author blog, show a bio on their entries ?>
		<div id="author-info">
			<div id="author-avatar">
				<?php echo get_avatar( get_the_author_meta( 'user_email' ), apply_filters( 'twentyeleven_author_bio_avatar_size', 68 ) ); ?>
			</div><!-- #author-avatar -->
			<div id="author-description">
				<h2><?php printf( __( 'About %s', 'twentyeleven' ), get_the_author() ); ?></h2>
				<?php the_author_meta( 'description' ); ?>
				<div id="author-link">
					<a href="<?php echo esc_url( get_author_posts_url( get_the_author_meta( 'ID' ) ) ); ?>" rel="author">
						<?php printf( __( 'View all posts by %s <span class="meta-nav">&rarr;</span>', 'twentyeleven' ), get_the_author() ); ?>
					</a>
				</div><!-- #author-link	-->
			</div><!-- #author-description -->
		</div><!-- #author-info -->
		<?php endif; ?>