Chopra is a Punjabi Khatri clan and belongs to the Bara-Ghar (12 House) Khatri section.
The earliest reference to this family name dates back to around 400 AD. One of the important characters of a famous Punjabi legend, "Raja Rasalu", is minister Mahita Chopra. Most scholars agree that Raja Rasalu is a historical figure that ruled from Sialkot and lived sometime between 400 and 500 AD. If this is true, then the Chopra family name developed by that time.
Other references are more recent. The father and son pair of the Diwan Sawan Mal and Mul Raj Chopra were successive governors of Multan under MaharajaRanjit Singh in the early 1800s.
"Imperial Rule in the Punjab: The Conquest and Administration of Multan, 1818–1881" by James Royal Roseberry, III. Journal of the American Oriental Society, Vol. 110, No. 1 (January–March 1990), p. 176