Yes, generally, but it does not have to be. 

The Tennessee Trust Code states as follows:

A trust advisor or trust protector, other than a beneficiary, is a fiduciary with respect to each power granted to such trust advisor or trust protector.

Why is this significant? The statute goes on to say:

In exercising any power or refraining from exercising any power, a trust advisor or trust protector shall act in good faith and in accordance with the terms and purposes of the trust and the interests of the beneficiaries.

Therefore, a third-party trust protector cannot wield power over the trust arbitrarily, but must act in a manner consistent with the grantor’s intent in creating the trust. If it fails to do so, the trust protector can be held liable for breach of fiduciary duty. 
The potential for liability may make some people reluctant to serve as trust protector. For this reason, the comments to the statute make clear that the trust protector need not be a fiduciary. The trust protector’s duty to act in good faith can be overridden by the terms of a trust, an agreement of the qualified beneficiaries, or a court order.

In that case, the trust protector would hold power in a non-fiduciary capacity. This would allow the trust protector to exercise its power under the trust in whatever manner the trust protector sees fit, so long as the exercise is consistent with the grant of power. It would also effectively render the trust protector unaccountable.

Given the extensive list of powers potentially available to a trust protector, you should not mindlessly waive the trust protector’s fiduciary duty. You should carefully weigh the pros and cons. Do you really want someone who is answerable to no one possessing the power to terminate the trust, force or veto distributions, or add beneficiaries? 
Source: T.C.A. § 35-15-1202(a)
Posted by Joel D. Roettger, JD, LLM, EPLS