Frederick Calvert, 6th Baron Baltimore, styled The Hon. Frederick Calvert until 1751, was an English nobleman and last in line of the Barons Baltimore. Although he exercised almost feudal power in the Province of Maryland, he never once set foot in the colony, and unlike his father, he took little interest in politics, treating his estates, including Maryland, largely as sources of revenue to support his extravagant, often scandalous lifestyle. In 1768 he was accused of abduction and rape by Sarah Woodcock, a noted beauty who kept a milliner's shop at Tower Hill. The jury acquitted Calvert, but he left England soon afterwards, and never recovered from the public scandal that surrounded the trial. Dogged by the criticism and poor health, he contracted a fever and died in Naples at the age of 40.

Baron Baltimore, of Baltimore, County Longford, was a title in the Peerage of Ireland. It was created in 1625 and ended in 1771, upon the death of its sixth-generation male heir, aged 40. Holders of the title were usually known as Lord Baltimore for short.