Nicholeen Viall is an American solar physicist who is the Chair of the American Astronomical Society's Solar Physics Division. Viall is known for her work on connecting dynamics of the solar corona to dynamics of the solar wind, based on observed variability of the corona-heliosphere system with both remote-sensing instruments and in-situ probes,[1] and for her work on understanding evolution of the plasma in the inner heliosphere.[2][3] She is the mission scientist for NASA's PUNCH mission, and a co-investigator on the ISS/CODEX and Parker Solar Probe/WISPR coronal imaging instruments.