Who is the creator or inventor of coefficient of determination (R-squared) ?
I know that Galton invented correlation.
A search on JSTOR shows that this term became quickly and widely adopted in the 1920s. It has been attributed to
Wright, Sewall. 1921. Correlation and causation. Journal of Agricultural Research 20: 557-585.
Wright was one of the giants of 20th century evolutionary biology.
For a rough but readable copy online, see here