Thomas Joannes Stieltjes, Dutch-French mathematician and academic (died 1894)

Thomas Joannes Stieltjes was a Dutch mathematician. He was a pioneer in the field of moment problems and contributed to the study of continued fractions. The Thomas Stieltjes Institute for Mathematics at Leiden University, dissolved in 2011, was named after him, as is the Riemann–Stieltjes integral.

December 29 is the 363rd day of the year in the Gregorian calendar; two days remain until the end of the year.