Dadarsi was a Persian general of Armenian origin and satrap of Bactria, who served under Persian king Darius I the Great (522–486 BCE). He was tasked with suppressing a revolt in Margiana.
The conquests of Cyrus the Great made them subjects of the Persians. They seceded at the time of Darius I's accession, but two expeditions, the first led by Dādarši, himself an Armenian, the second under Vahumisa, a Persian, ended their rebellion (DB 2.37-63).