Import Google Tasks into Microsoft Outlook - Google-Tasks-Backup/tasks-backup GitHub Wiki

To import Google Tasks into Outlook 2007

1. Export tasks from GTB in "Outlook CSV" format
2. In Outlook 2007, go to File > Import and Export
3. Select "Import from another program or file" and click [Next >]
4. Select "Comma Separated Values (DOS)" and click [Next >]
5. [Browse ...] to select the .csv file exported by GTB and click [Next >]
6. Select "Tasks" as the destination folder and click [Next >]
7. Click [Finish]

I presume that the steps would be similar for other versions of Outlook