An old pureblood family dating back to the pre-colonial days in America, the Collins family has always primarily lived in Pennsylvania, with a few recent exceptions. The family is headed by Thomas Collins II. He and his wife, Cara, had four sons, Thomas III, Jared, Quincy and Owen.

Thomas III married Rose and had two children, Thomas IV and Stephanie. Thomas IV married a British pureblood named Kimberly. Thomas IV and Kimberly's children, the uncreatively named Thomas V and the more creatively named Olympia attended Hogwarts, rather than an American school. After graduation, Olympia went on to Sapienti University of Magic where she was sorted into Merlo. Thomas the Umpteenth is married to the (in Olympia's opinion), "completely horrid" Miss Camilla Fairbanks, of England.

Jared married Cynthia and had three kids, Elliot, William and Annamarie. Elliot's children are Elliot II, Jared II, and Anna. William's children are Jeremy and Natalie.

Quincy married Tabitha. They had one son named Lawrence who had a daughter named Sabrina.

Youngest son, Owen married Amelia Brockert from Colorado. They had one son, Gary. Unlike his Collins cousins, Gary was not placed in an arranged marriage due to his maternal family's denouncement of the practice. This led Gary, (who was a wanderer and alcoholic) to become the first member of either the Collins or Brockert families to marry a Muggle in centuries. He married Dinah Wilkins and produced a daughter, Lily. This marriage did not last. Gary and Dinah divorced when Lily was six and Dinah made sure Gary had no contact with his daughter. Gary got remarried to Felicity Snyder from a pureblood family in Wisconsin and had two daughters named Autumn and Willow. He has also since reunited with Lily, during her third year of school and second year at Sonora.