James Andrew Donnelly Deeny (7 November 1906 – 3 April 1994) was the Chief Medical Adviser of the Republic of Ireland and a senior administrator in the World Health Organization.

In 1930, he went to Vienna where he worked in The State Service Institute under the auspices of the American Medical Association, specializing in the technology of tuberculosis.

[1] He first came to prominence in the 1930s after publishing a study on the nutritional deficiencies of male factory workers in Lurgan in the Journal of the Ulster Medical Society.

[2] Treating two Lurgan "blue men", he discovered the use of ascorbic acid in the treatment of familial idiopathic methemoglobinemia.

[2] Some time after taking up the Dublin position, Deeny became aware of extremely high infant mortality rates in the Bessborough mother and baby home run by the Sisters of the Sacred Heart order in Cork.

Such a challenge to church personnel was very unusual for the time and a complaint was made by Bishop Daniel Cohalan of Cork to the Papal Nuncio.

The Nuncio visited Taoiseach, Eamon De Valera, but on seeing the report on the matter he had to agree that the right steps had been taken.

[5] In May 1948, Deeny attended the first assembly of the World Health Organization (WHO) in Geneva as chief of the Irish delegation.

In 1971, he became Scientific Adviser to Pope Paul VI and helped to set up Cor Unum, the Pontifical Council for Human and Christian Development.

[4] In 2012 a Blue Plaque in his memory was erected at his former residence and place of medical practice in Lurgan Town Square.