Exhibit 21.1

Subsidiaries of Align Technology, Inc.

The registrant’s principal subsidiaries as of December 31, 2015, are as follows:

Entity

Align Technology De Costa Rica, SRL, Costa Rica

Align Technology, B.V., the Netherlands

Aligntech de Mexico, S. de R.L. de C.V.

Cadent, Inc.

Align Technology, Ltd.

Invisalign Australia Pty Ltd