Breach of fiduciary duty is a cause of action or claim in civil litigation (lawsuits) that provides the legal basis for a person or entity to recover its damages/losses when there is a special relationship based on trust and confidence (attorney and client or trustee and beneficiaries) and the party who owes the fiduciary duty breaches its duty of loyalty (conflict of interest) or duty of care (informed judgment in decision-making).

In Maine, a breach of fiduciary duty occurs when an individual or entity, who is obligated to act in the best interest of another due to a special trust relationship, fails to do so. This breach can involve a conflict of interest or a failure to make informed decisions in the interest of the party to whom the duty is owed. Fiduciary relationships are often found between attorneys and clients, trustees and beneficiaries, corporate directors and shareholders, and other similar relationships where trust and confidence are paramount. When a fiduciary breaches their duty, the affected party may file a civil lawsuit to recover damages resulting from the breach. Maine courts will evaluate whether the fiduciary acted in good faith, with the care an ordinarily prudent person in a like position would exercise under similar circumstances, and in a manner the fiduciary reasonably believes to be in the best interests of the beneficiary. The specific statutes and case law governing fiduciary duties in Maine will provide the framework for any legal proceedings related to such a breach.