He graduated from Hampden–Sydney College in south central Virginia in 1815 and practiced law in Fayetteville, North Carolina.

Strange was elected as a Jacksonian (later Democrat) to the United States Senate to fill the vacancy caused by the resignation of Willie Person Mangum and served from December 5, 1836, to November 16, 1840, when he resigned and resumed the practice of law in Fayetteville, where he died on February 19, 1854, and was buried in the family burial ground at Myrtle Hill, near Fayetteville.

In this role Strange served as the escort for the Marquis de Lafayette when he visited Fayetteville on March 5, 1825.

The 1820 Census for Fayetteville, North Carolina shows that Robert Strange was the enslaver of (4) black people.

This article incorporates public domain material from the Biographical Directory of the United States Congress