Due Diligence is the process of investigating a business, person, management team, and/or property before making a commitment to enter into a transaction or relationship with the entity or person, subject to the due diligence investigation. Most due diligence investigations take place before acquiring a business or real estate. The origin of the term comes from the Securities Act of 1933.

Depending upon the purpose of the due diligence investigation, experts in various fields will be used as part of the process. Experts often include attorneys, accountants, engineers, contractors, appraisers, insurance consultants, and underwriters.