Dandridge was the son of John Dandridge, a London member of the company of painters and stainers, and his second wife, Ann Dandridge (whose maiden name is not known). He was born on December 29, 1689. Several of his siblings were born in their father’s native Oxfordshire, but Dandridge’s birthplace is uncertain. Commissioned a lieutenant in the Royal Navy on October 20, 1709, he left active duty within a few years and sometime before 1715 sailed to Virginia, probably in company with his brother, John Dandridge, later the father of Martha Dandridge Custis Washington. Dandridge lived at Hampton, where he owned a wharf and a ship and was a merchant. In 1715 Lieutenant Governorcommissioned him to carry soldiers in his sloop William from Hanover County to Charleston, South Carolina. Dandridge may have accompanied Spotswood on his expedition to the Shenandoah Valley the following year. The members of that party later received commemorative golden horseshoes.
By late in July 1715 Dandridge had married a young widow, Euphan Wallace Roscow. They had one son before her death on April 22, 1717. Two years later Dandridge moved to Elsing Green, a large King William County estate that he acquired when he married Unity West on March 17 or 18, 1719. One of their four daughters and one of their two sons married children of Alexander Spotswood.
On June 1, 1727,appointed Dandridge to the governor’s Council. Dandridge took his seat on September 11, at which time the news of the king’s death and the accession of George II were officially proclaimed in Williamsburg. On the following December 14 the lieutenant governor appointed Dandridge one of the commissioners to survey the boundary between Virginia and North Carolina. With William Byrd and Richard Fitzwilliam, he accompanied both surveying parties that were in the field from February 27 to April 9 and from September 17 to November 22, 1728. In Byrd’s private manuscript account of the surveying expeditions, usually designated the Secret History of the Dividing Line and not published until the twentieth century, he assigned type names to all of the main characters of his fanciful narrative. He called Fitzwilliam “Firebrand” and Dandridge “Meanwell.” Byrd’s Secret History offers the best information available about Dandridge’s personality. Much of the dramatic tension in the story comes from the conflict between the irascible Fitzwilliam and the prudent, even-tempered Dandridge. From the pages of Byrd’s narrative, Dandridge emerges as a good-natured gentleman, a keen conversationalist, and a spirited companion. In a letter of introduction to the bishop of London, , another member of the Council, confirmed Byrd’s evaluation of Dandridge and called him “a very honest Gentleman.”
In August 1734 Dandridge obtained a one-year leave of absence from the Council in order to return to England, where he intended to resume his naval career. He was commissioned a lieutenant and extended his leave of absence from Virginia for two more years, but he eventually found a way to return home while remaining in the navy. Dandridge became commander of a ship assigned to patrol the coast of Virginia and the colonies to its south. Though he had been absent from Virginia for more than three years, he very much wanted to continue serving on the Council once he returned, and he successfully requested permission from the absentee royal governor,, to do so.
Promoted to commander on April 11, 1738, and given charge of the twelve-gun sloop Wolf, Dandridge also received from the second duke of Montagu that same month a handsome, inscribed sword that a descendant presented to the Virginia Historical Society in 1969. Although Dandridge had difficulty fitting out the ship and completing his crew, he sailed in the Wolf from Portsmouth, England, before the end of June. Traveling by way of Madeira, he encountered stormy weather that battered the ship and left less-seasoned crewmembers seasick. Serious illness struck others, who died or had to be put ashore. Dandridge reached Virginia on September 29, 1738. The following week the Virginia Gazette reported his arrival and announced his mission: “to protect the valuable Trade of this Country, against any Insults that may be attempted upon it.” During the following two years he spent much time aboard the Wolf cruising the Virginia and Carolina coasts.
Dandridge was promoted to captain in November 1741 and took command of the forty-four-gun Southsea Castle, which he sailed from England to Virginia. He arrived early in 1742, in time to take part in the British attack on Saint Augustine and the siege of Cartegena during the War of the Austrian Succession. After being ordered back to England the next year, he attended the Council for the last recorded time on August 4, 1743. Dandridge was given command of the forty-gun Mary Galley the following July, but he died little more than a month later, at Greenwich, England, on August 28, 1744.