The City Ethics Board was created by a 1963 Charter Amendment to enforce certain new prohibitions against conflicts of interest. Financial disclosure requirements were added to the law in 1974.

In 1981, the State enacted a new, comprehensive Maryland Public Ethics Law; among other things, the new State law mandated each local jurisdiction to adopt its own, local ethics law that would be "similar" or, in some instances, "substantially similar" to the State's. Accordingly, in 1982 and 1985, the City Charter and the City Code were revised and expanded to conform to that State law.

Effective January 1, 2005, the City Ethics Law was extensively revised, expanded, and clarified by Ordinance 04-795 {“Ethics – ‘Raising the Bar’”}, to reflect many “lessons learned” over the preceding two decades. More recently, Ordinance 10-267 {“Public Ethics Law – Clarifications and Expanded Coverage”} redefined and further clarified certain terms (e.g., “business with the City”) and clarified and expanded the scope of those with whom certain transactions are prohibited (e.g., persons from whom gifts may not be accepted). And Ordinance 10-272 {“Public Ethics Law – Ethics Board Composition, Tenure, etc.”} reconstituted the Board 's membership in its current form.

Ordinance 20-354 {“Ethics Board – Administration and Staff”}, effective on October 10, 2020, designated the Baltimore City Inspector General as the Executive Director of the Board of Ethics. The Inspector General may allocate staff from the Office of the Inspector General to assist the Executive Director and the Board of Ethics in their responsibilities.