A fiduciary duty arises out of a special relationship between what’s called a principal and an agent. For example, an officer of a corporation owes a fiduciary duty to that corporation. It’s a duty of care. Generally, that duty is not to act contrary to the interest of the employer, that or self-dealing, which harms the company. Other fiduciary duty examples are a trustee of a trust. A lawyer has a fiduciary duty.