Exhibit 21.1

Subsidiaries of Align Technology, Inc.

The registrant’s principal subsidiaries as of December 31, 2013, 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.

Cadent, Ltd.

Invisalign Australia Pty Ltd