The first Service Pack for Office 2013 has been released just a little over 1 year after its original release.
If you have installed Office 2013 via a msi-installer, then you can install it by using the standalone installer listed below or via Microsoft Update when you have it configured to also check for Office Updates.
When you are using Office 2013 as part of an Office 365 subscription, then the update will be installed automatically after a few days, or you can force the update detection by temporarily disabling Automatic Updates in the File-> Office Account section and then directly enabling it again.
For instructions about how to create an installation DVD containing Office 2013 with Service Pack 1 slipstreamed into it see: Slipstream Office 2013 setup with SP1
Download: Service Pack 1 for Microsoft Office 2013 (KB2817430) 32-Bit Edition
Download: Service Pack 1 for Microsoft Office 2013 (KB2817430) 64-Bit Edition
Download: Microsoft Office Language Interface Pack 2013 Service Pack 1 (32- and 64-bit)
Download: Microsoft Office 2013 Service Pack 1 Changes (Excel sheet)
Download: Microsoft Service Pack Uninstall Tool for Microsoft Office 2013 (coming soon)
Download: Office 2013 Policy Templates (SP1 release)
View: All other available Office 2013 SP1 packages for Desktop products
View: All other available Office 2013 SP1 packages for Server products