To add a footer in LaTeX without displaying the page number, you can use the fancyhdr package, which provides extensive control over headers and footers. First, include the package in the preamble of your document with \usepackage{fancyhdr}. Then, set up the page style to fancy with \pagestyle{fancy}. To modify the footer, you can use commands such as \fancyfoot[L]{} for the left footer, \fancyfoot[C]{} for the center footer, and \fancyfoot[R]{} for the right footer.