Gainsborough or Gainsboro may refer to:

• Gainsborough, Ipswich, Suffolk, England
  • Gainsborough Ward, Ipswich
• Gainsborough, Lincolnshire, a town in England
  • Gainsborough (UK Parliament constituency)
• Gainsborough, Saskatchewan, Canada
• Gainsboro, Roanoke, Virginia
• Gainesboro, Tennessee
• Gainesboro, Virginia

• Earl of Gainsborough, a title in the peerage of England and the peerage of the United Kingdom
• Humphrey Gainsborough (1718–1776), English minister and engineer
• Thomas Gainsborough (1727–1788), English painter
• William Gainsborough (died 1307), Bishop of Winchester

• Aerith Gainsborough, a fictional character from Final Fantasy VII
• Gainsborough (crater), on the planet Mercury
• Gainsborough (horse), the 1918 Triple Crown Champion of English Thoroughbred Racing
• HMS Gainsborough, two ships of the Royal Navy
• Gainsborough Pictures, a London-based film studio, active between 1924 and 1951
  • Gainsborough melodramas, a group of films made by the studio
• Gainsborough chair, a type of chair made in 18th century England
• Gainsborough hat, a hat in the style of those in Thomas Gainsborough's paintings
• Gainsboro, a color in the X11 color scheme
• a mullein (plants in the genus Verbascum) cultivar