More or less, yes. Though it is rather different.
Firstly, Mac OS X does its own defragmenting "on the fly", defragmenting files as they are written. However, just because it doesn't need defragmenting doesn't mean it doesn't need any maintenance at all.
In the Applications - Utilities folder you can find Disk Utility. You can also access this on the Mac OS X install CD by booting from the CD and choosing it in the "Installer" menu. In here there is a 'First Aid' tab that can be used to verify and repair the integrity of a disk, and its permissions.
As for disk cleanup ... there are a number of things that you can do. Since browser caches tend to fill up pretty quickly, you can delete the cache files from your Library folder in your home folder. In Safari you can choose "Empty Cache" from the Safari menu.
All the other cleanups and checks will run periodically but it is possible (though usually unneccessary) to start them manually by opening a terminal and typing:
sudo periodic daily
sudo periodic weekly
sudo periodic monthly
(you will be prompted for your password)
Hope this helps.
