DHS Private Sector Office Engagement Act of 2014 - Amends the Homeland Security Act of 2002 to replace provisions directing the Secretary of Homeland Security (DHS) to appoint a Special Assistant responsible for private sector matters with provisions establishing within DHS a Private Sector Office, to be headed by an Assistant Secretary for Private Sector Coordination.

Establishes as the Office's mission to: (1) create and foster strategic engagement with the private sector to enhance the primary mission of DHS to protect the United States; and (2) conduct ongoing economic impact analysis to reduce the burden of DHS decisions, regulations, and initiatives on the private sector and the U.S. economy.

Includes among the Assistant Secretary's responsibilities:

• to create a strategic plan for the Office;
• to advise the Secretary regarding the impact of DHS's policies, regulations, processes, and actions on the private sector;
• to analyze the economic impact of changes in homeland security policy;
• to determine actions needed to reduce associated homeland security burdens on the private sector;
• to foster strategic engagement with the private sector to improve homeland security;
• to promote to the private sector best practices regarding cyber security and critical infrastructure protection;
• to promote and develop public-private partnerships to provide for collaboration and mutual support to address homeland security challenges; and
• to collaborate with the Chief Human Capital Officer to facilitate the DHS Loaned Executive Program.

Terminates the Office on December 31, 2018. Directs the Secretary to conduct an assessment of the Office concurrently with the next Quadrennial Homeland Security Review.