Robert Coles (c. 1600 – 1655) was a 17th-century New England colonist who is known for the scarlet-letter punishment he received in the Massachusetts Bay Colony and his role as an original proprietor of Providence and co-author of the Providence Combination of 1640, which established the first secular, representative democracy in America.

Coles arrived in Massachusetts Bay in 1630 on the Winthrop Fleet where he became a first settler of the towns of Roxbury and Agawam, now Ipswich, and an early settler of Salem. After repeated fines for drunkenness, he was ultimately sentenced to wear a red letter "D" as a badge of shame for a year, an event that may have served as an inspiration for Nathaniel Hawthorne's 1850 novel The Scarlet Letter.

He left Massachusetts Bay to join Roger Williams at Providence where he was one of the 13 original proprietors and a founding member of the First Baptist Church in America. He was a first settler of Pawtuxet and an early settler of Shawomet, now the Rhode Island towns of Cranston and Warwick.

The Providence Combination of 1640 was signed by both men and women in Providence and contained 12 articles that defined borders, created elected arbitrators, and affirmed liberty of conscience.

After Coles's death his family moved to Long Island, New York. Three of his sons founded the city of Glen Cove, New York, while three of his daughters married into the Townsend family who engaged in civil disobedience to promote the separation of church and state.

Coles arrived in New England in the summer of 1630 as a passenger in the Winthrop Fleet, and was among the first settlers of the town of Roxbury. In October of that year he petitioned the Massachusetts Bay Colony's General Court in Boston to become a freeman and in 1631 he took the freeman's oath. He was a founding member of the First Church of Roxbury, which was a non-separating Congregationalist church established in 1631, and in 1632 he was one of two townsmen elected to represent Roxbury in the General Court. During his term, Massachusetts Bay became the first colony to adopt formal arbitration laws.

In 1633, Coles was in the first company, led by John Winthrop the Younger, that went to Agawam where he was granted a large home lot on the Ipswich River at present-day East and Cogswell Streets and 200 acres—a property now called Greenwood Farm—on the neck of land north of town. He moved to Salem in 1635 where he received a home lot in town and 300 acres of farmland south of Felton Hill "in the place where his cattle are by Brooksby."

In 1631, Coles was fined five marks (about £3 then and US$850 in 2022) for drunkenness aboard the Friendship and at Winnissimet, now Chelsea. The Friendship was carrying two hogsheads (more than 120 gallons) of flavored mead called metheglin. Coles's fellow carousers—who were not pious Puritans—included Edward Gibbons, a former polytheist "who chose rather to Dance about a May pole...than to hear a good Sermon" and Samuel Maverick, a wealthy Anglican "very ready to entertain strangers." In 1632, Coles was again fined for drunkenness, this time in Charlestown. In addition to his fine of £1 he was required to appear before the General Court and the Court of Assistants to publicly confess.