|  Caution: | Mediawiki installations after MediaWiki 1.35.0 should be using $wgLogos as $wgLogo is no longer supported.[1] | 
| Server URLs and file paths: $wgLogo | |
|---|---|
| The URL of the site logo. | |
| Introduced in version: | pre 1.1.0 | 
| Removed in version: | still in use | 
| Allowed values: | (relative path or absolute URL) | 
| Default value: | "{$wgScriptPath}/resources/assets/change-your-logo.svg"(1.38+)
 | 
| Other settings: Alphabetical | By function | |
Details

The URL of the site logo (i.e. the image displayed in the upper-left corner of the page in most MediaWiki installations). Either a fully-qualified URL or a relative path from DOCUMENT_ROOT. If it's a relative path, it has to start with a slash (a file in DOCUMENT_ROOT is /file.png, not file.png).
The logo is expected to be 135 × 135 pixels. A bigger size can be used by modifying the site CSS (and smaller sizes are possible with no changes). Note that if you use a bigger image, MediaWiki will not resize this image! Instead, the image will be cut off so that only part of it (the upper left-hand corner to be precise) will be visible. If this corner is completely white, it might look like the image does not display although in fact it does.
|  Caution: | Do not simply overwrite the default logo installed with MediaWiki ( /resources/assets/change-your-logo.svg); this file will automatically be overwritten when you upgrade and your changes will be lost. | 
Examples
 Upload your logo file onto your server.
 Let's say it ends up as /images/4/47/mylogo.png.
 Then you can use it as your site logo by adding this line to LocalSettings.php:
$wgLogo = $wgScriptPath . '/images/4/47/mylogo.png';
Make sure that you add this line below the definition of $wgScriptPath! Otherwise, $wgScriptPath will still be undefined and the logo will not display.
Vary logo per language
With CSS, it is possible to use a different logo for each interface language:
.mw-wiki-logo:lang(ar) {
	background-image: url( /logos/ar.png ) !important;
}
.mw-wiki-logo:lang(de) {
	background-image: url( /logos/de.png ) !important;
}
See also
- How do I change the logo?
- $wgLogos
- $wgLogoHD
- $wgFavicon
- $wgAppleTouchIcon