The 39-year-old star of TV's "The Big Bang Theory" did not identify his long-term partner or go into detail about his private life.
The Times interview coincides with Parsons' upcoming return to Broadway in "Harvey" after a successful run playing a young gay activist in "The Normal Heart" last summer.
In the article, journalist Patrick Healy writes, "'The Normal Heart' resonated with him on a few levels: Mr. Parsons is gay and in a 10-year relationship, and working with an ensemble again onstage was like nourishment, he said."
E! News said Parsons does not speak publicly about his personal life, but is often seen with his boyfriend at awards shows and other entertainment industry events.