Opportunity Kindling New Options for Career and Knowledge Seekers Act or Opportunity KNOCKS Act - Amends the Internal Revenue Code and the Federal Unemployment Tax Act to deem approved by the Secretary of Labor any state laws that provide unemployment compensation to an individual for any week while in training, including: (1) any program on a state's eligible training provider list developed under the Workforce Investment Act of 1998, or (2) any coursework necessary to attain a recognized postsecondary credential if that individual is likely to exhaust his or her regular unemployment compensation.

Defines "recognized postsecondary credential" as a credential consisting of an industry-recognized certificate, a certificate of completion of an apprenticeship, or an associate or baccalaureate degree.

Amends the Federal-State Extended Unemployment Compensation Act of 1970 and the Supplemental Appropriations Act, 2008 to authorize a state unemployment compensation agency to elect to approve job training or educational programs for purposes of an individual receiving extended or emergency unemployment compensation while in training.