Simon Bradstreet (March 18, 1603–March 27, 1697) was a colonial magistrate, businessman and governor of the Massachusetts Bay Colony.

Simon Bradstreet was born in Horbling, Lincolnshire. His father was the rector of the parish church. It is unclear whether Bradstreet received degrees from Emanuel College at Cambridge, but Bradstreet certainly attended the college for the two years before his emigration. He must have become associated with Puritan elements at this time, as he was married to the future poet Anne Dudley while still in England. She was the daughter of Puritan leader Thomas Dudley. Dudley and others recognized Bradstreet's administrative abilities, and he was persuaded to leave for the fledgling Massachusetts Bay Colony in 1630.

Bradstreet was chosen to fill several important positions in colonial affairs, and he served as an assistant in the upper house of the General Court for most of his life. During his first twenty years in the colony, he was heavily involved in business pursuits, as well as the founding of new towns. In 1661, he was chosen as an envoy to the court of Charles II, that monarch having recently been restored to power. In 1679 Bradstreet was chosen governor of the colony. He would turn out to be the last governor under the original charter. In 1686, the colony was denied its right to self-rule, and Sir Edmund Andros was installed as governor. Bradstreet served briefly as governor again after Andros was overthrown, but England replaced him with Sir William Phips in 1692. Bradstreet continued to serve in government until his death in 1697, in Salem, Massachusetts.

Simon Bradstreet was married again after the death of his first wife, to Ann Gardner, the widow of Captain Joseph Gardner of Salem.