John James Walker FRS (1825–1900) was an English mathematician.

As his family was of Irish descent, he went to study mathematics and physics to Trinity College Dublin where he graduated in 1846 and mastered in 1857.

[1] From 1853 to 1862 he was private tutor of the rich family Guinness, the most famous brewers of Ireland.

In 1888 he retired from the academy and he devoted to original research the rest of his live.

[2] His original research was mainly in higher algebra (analysis of plane curves) and in quaternions (considered as the best instrument of research).