John Welsh (November 9, 1805 – April 19, 1886) was an American merchant and diplomat who served as United States Minister to the Court of St. James's from 1877 to 1879.

He received a good preparatory education, including a classical course, and began in the mercantile business at a very early age.

He took an active interest in founding the Episcopal hospital, he made himself responsible for the entire building fund amounting to $331,000, of which he personally contributed $41,000.

[3] In 1864, Welsh was chairman of the executive committee of the great Sanitary Fair held in Logan Square, Philadelphia, which raised $1,500,000 in money and supplies for the promotion of the health and comfort of soldiers and sailors in the United States Army and Navy.

After the exhibition closed, the board of directors, in recognition of his services, voted him a gold medal, and a number of prominent persons presented him $50,000 as "a perpetual commemoration of the sincere gratitude of the citizens of Philadelphia."

[5] On October 30, 1877, President Rutherford B. Hayes appointed Welsh minister to the United Kingdom, which he held until his resignation, August 31, 1879.