Helen Rhoda Arnold Quinn (born 19 May 1943) is an Australian-born particle physicist and educator who has made major contributions to both fields.

Her contributions to theoretical physics include the Peccei–Quinn theory which implies a corresponding symmetry of nature[2][3](related to matter-antimatter symmetry and the possible source of the dark matter that pervades the universe) and contributions to the search for a unified theory for the three types of particle interactions (strong, electromagnetic, and weak).

[9] Working with Howard Georgi and Steven Weinberg, Quinn showed[10] how the three types of particle interactions (strong, electromagnetic, and weak), which look very different as we see their impact in the world around us, become very similar in extremely high-energy processes and so might be three aspects of a single unified force.

One consequence of this theory is a particle known as the axion which has yet to be observed but is one candidate for the dark matter that pervades the universe.

"[13] She was elected to the National Academy of Sciences (NAS) while she was a staff member at SLAC;[14][15] she was soon made a full professor of physics at Stanford.

As a member of NAS, she joined the Board on Science Education of the National Research Council and has served on a number of its studies.

[19] In 2015, the President of Ecuador appointed her as a member of the board (Comision Gestora) charged with leading the new National University of Education.