Nelson Dingley Jr. (February 15, 1832 – January 13, 1899) was a journalist and politician from the U.S. state of Maine.

However, he never practiced law and instead became proprietor and editor of the Lewiston, Maine Journal, holding this post for more than twenty years.

Dingley was elected as a Republican to the 47th Congress to fill the vacancy caused by the resignation of William P. Frye.

Reputedly "destitute of humor but soundly versed in finance", Dingley was chairman of the U.S. House Committee on Ways and Means in the 54th and 55th Congresses.

Dingley had been reelected to the 56th Congress and was succeeded by Charles E. Littlefield upon his death in Washington, D.C., on January 13, 1899.