One of its high-profile uses is to house systems that help run the Australian Open tennis tournament.
SoftLayer customer ChannelPace, a business contact management provider, welcomed the new location.
CEO Greg Furlong said "IBM Cloud's growing number of SoftLayer data centres - all connected via SoftLayer's global network—make it easy for us to expand and grow our business.
"With the Melbourne data centre and new Sydney data centre, we have the option of data redundancy right here in our backyard."
As an introductory offer, new and existing SoftLayer customers can get up to US$500 off their first bill for servers and services in the Sydney data centre.
Other SoftLayer centres in the APAC region include Hong Kong, Singapore and Tokyo.