As written on blogs.office.com
Today, as part of our deep and continued commitment to make Office 365 the most trusted cloud service for productivity, we are announcing the general availability of Office 365 from our new cloud datacenters in Seoul and Busan, South Korea. We are pleased to be the first global cloud productivity provider offering customer data residency in South Korea.
Since October 2014, we have expanded our global cloud footprint and opened new datacenter regions in Japan, Australia, India, Canada, U.K. and now South Korea. In addition to the same highly secured productivity capabilities already enjoyed by Office 365 customers all over the world, these new datacenter regions add local data residency, failover and disaster recovery to help effectively address the legal and regulatory needs of customers in industries like banking, public sector and healthcare.
To learn more about Office 365 and our security and compliance capabilities, please visit our website and the Office 365 Trust Center.