Robert Emmet Monaghan (July 24, 1822 – June 29, 1895) was an American politician from Pennsylvania.

His father emigrated from Fermanagh, Ireland, and was involved in the revolution led by Robert Emmet.

His father worked as a clerk, farmer, and was justice of the peace and a Democratic candidate of the state legislature.

[1] Monaghan taught for a time and then worked as collector at the Pennsylvania canal in Liverpool for three years.

He was appointed by Governor Robert E. Pattison, along with Charles R. Buckalew and Ovid F. Johnson for the "promotion of the uniformity of legislation in the United States".

[3] Monaghan served on the council of the borough of West Chester and as chief burgess.

He was an incorporator and served as a member of the board of directors of the Union Trust Company of Philadelphia.