What is James T. Kirk's ethnic background?

Question

Many of the main human characters in Star Trek have clear ethnic backgrounds or identities. For example, Picard is French, Chekov is Russian, Sisko is Creole, Scotty is Scottish, Sulu is Japanese (even when being played by a Korean actor), O'Brien is Irish, etc.

What is known about James T. Kirk's ethnic background? Canon establishes that he was from Iowa, and his name sounds similar to a North Germanic root meaning church (c.f. Swedish kirke), so I might guess that he is a descendant of Scandinavian settlers in the US Midwest. Another possibility is that his name derives from Lowland Scots kirk, also meaning church, possibly making him a descendant of Scots Protestant settlers in Appalachia ("Hillbillies") who later moved west onto the prairies in search of cheaper farmland. Is this discussed anywhere?

Note that I'm not asking about the provenance of the name Kirk specifically, but using it as a means to mention probable scenarios.

Answer 1

The "Autobiography of James T. Kirk", told in-universe by Kirk himself and licensed by Paramount has some additional information to offer about Kirk's ethnicity. In short, his primary ethnic makeup appears to be broadly Caucasian (presumably Scottish given that the Kirk name evidently predates his American ancestry in the 1800s) as well as part-Italian(?) and part-Sioux on his mother's side.

The house was four bedrooms, two floors, brick and wood. It was built using authentic materials and was a perfect copy of the house that had stood on the property for over 100 years in the 19th and 20th centuries. The property had belonged to seven generations of Kirks; it was family legend that my great-great-great-great-great-great-great-grandfather, Franklin Kirk, purchased the farm in 1843 from Isaac Cody, who was the father of William F. “Buffalo Bill” Cody. My ancestors in the modern era let caretakers manage it, until my grandparents moved back there when they retired. My father, George Kirk, also always had a strong desire to live there.

He had grown up as one of the original “Starfleet brats”; his father, Tiberius Kirk, was already in his twenties when Starfleet Academy was founded, and though he applied, he wasn’t accepted. Still wanting to get out into space, Tiberius signed on in ordnance and supply, eventually serving on several of the then-new starbases. He met and married my paternal grandmother, Brunhilde Ann Milano, a nurse, on Starbase 8. My father was born there on December 13, 2206.

and

My mother, born Winona Davis, was also from a spacegoing family; her father, James Ogaleesha Davis (his middle name, as befit his heritage, was Native American Sioux, although I never did find out what it meant), was in the first graduating class of Starfleet Academy; his wife, Wendy Felson, was in the third. My maternal grandfather was an engineer, my maternal grandmother a physician, and their daughter, my mother, attended the academy and decided she wanted to be an astrobiologist. She was four years younger than my father, and had him as an instructor in her Introduction to Federation History class.