Ettore Bortolotti (6 March 1866 – 17 February 1947) was an Italian mathematician.

He studied mathematics under Salvatore Pincherle and Cesare Arzelà in Bologna.

There, he became dean from 1913 to 1919, then moved back to the University of Bologna, where he retired in 1936.

Bortolotti must also be considered a differential geometer and a relativist too.

In fact, in the year 1929, he commented on the geometric basis for Einstein’s absolute parallelism theory in a paper entitled "Stars of congruences and absolute parallelism: Geometric basis for a recent theory of Einstein".