Charles Calvert, 5th Baron Baltimore, FRS (29 September 1699 – 24 April 1751) was an English politician and colonial administrator who served as the proprietary governor of the Province of Maryland.

He inherited the title to Maryland aged just fifteen, on the death of his father and grandfather, when the colony was restored by the British monarchy to the Calvert family's control, following its seizure in 1688.

Like the rest of his Calvert family, Charles had been raised a Catholic but was withdrawn from his Jesuit school when his father Benedict converted to Anglicanism, largely for political reasons.

Henceforth father and son would worship within the Church of England, much to the disgust of Charles Calvert, 3rd Baron Baltimore, who upheld his Catholic faith, despite the political drawbacks, until his death in 1715.

Benedict was unimpressed, and his younger brother Cecil wrote to him that family opinion in England was appalled at Captain Calvert's behaviour, and "thinks him mad".

[7] Unfortunately for the Marylanders, Charles unwittingly agreed to a settlement of the territorial dispute with Pennsylvania, based on an inaccurate map, using calculations of latitude and longitude which were either wrong or were deliberately omitted.

[8] Upon realizing the scale of his deception, Lord Baltimore reneged on the agreement, but in 1735 The Penns brought proceedings in the Court of Chancery in London to enforce compliance.

[8] Chancery proceedings were notoriously slow and a final verdict was not reached until 1750, when Lord Chancellor Hardwicke found in favour of the claims of the Pennsylvanians in every respect.

[citation needed] In 1732 Calvert returned to England, again leaving the government of Maryland in the hands of Governor Samuel Ogle, and pursued a successful career in English politics.

He was a Fellow of the Royal Society and a friend of fourth-cousin, Frederick Louis who was Prince of Wales and the eldest son of King George II of Great Britain.

His mother's identity is not clear but H. S. Lee Washington, writing in the New England Historic Genealogical Society Register in July 1950, suggests that she was Melusina von der Schulenburg, Countess of Walsingham.

[18] In 1742, aged about ten or twelve years,[19] the young Benedict was escorted to America and placed in the care of Dr. George H. Steuart, an Annapolis physician and a political ally of the Calverts.

Unlike his father, Frederick Calvert took little interest in politics, treating his estates, including Maryland, as mere sources of revenue to indulge his appetites, which were considerable.