James Joseph Nealon (December 15, 1884 – April 2, 1910) was a professional baseball player.
He was born in Sacramento, California, and died in San Francisco, at the age of 25.
He was a first baseman over parts of 2 seasons (1906–1907) with the Pittsburgh Pirates.
In his rookie season in 1906, he tied for the National League lead in RBIs with Harry Steinfeldt.
The next year, he contracted tuberculosis, ending his baseball career.
He subsequently died of typhoid pneumonia at the age of 25.