Madison users access MyUW at https://my.wisc.edu .

Employees of the Universities of Wisconsin who are not Madison employees access MyUW at https://my.wisconsin.edu .

But wait! There's more! 

MyUW hosts several campus-specific hostnames. 

The additional campus-specific hostnames are:

https://my.uwex.edu (also serves UW Flexible Option students)

https://my.uwgb.edu 

https://my.uwm.edu 

https://my.uwp.edu

https://my.uwplatt.edu 

https://my.uwrf.edu 

https://my.uwsp.edu 

Using these hostnames has the convenience of asking the user to log in using the appropriate campus-specific Identity Provider (IdP) rather than relying upon the Wisconsin Federation Discovery Service, whereat a user must self-identify which campus IdP they will use.