Dai has received several honors and awards, among them:
* 1985: Camille and Henry Dreyfus Foundation New Faculty Award
* 1988: Sloan Fellowship
* 1989: The Camille and Henry Dreyfus Foundation Teacher-Scholar Award
* 1990: Coblentz Award in Spectroscopy
* 1992: Fellowship of the American Physical Society
* 1994: Alexander von Humboldt Award for Senior US Scientists
* 1995: Philadelphia Section Award, American Chemical Society
* 2000: Guggenheim Fellowship
* 2006: Ellis Lippincott Award for Spectroscopy of the Optical Society of America
* 2009: Distinguished Achievement Award, the Institute of Chinese Engineers in the U.S.
* 2010: Fellowship of the American Chemical Society
* 2012: Langmuir Lecturer Award, Division of Colloid and Surface Chemistry, American Chemical Society
* 2013: Michael P. Malone International Leadership Award, Association of Public and Land Grant Universities
* 2017: Knight Order of the Italian Star, Government of Italy
* 2017: Distinguished Alumni Award, National Taiwan University
* 2019: Hai-Lung Dai Festschrift, Journal of Physical Chemistry, American Chemical Society