Ugly Betty creator Silvio Horta has been found dead in Miami, the show's actresses said Tuesday.
Horta's agent said a statement from the family was expected shortly. Although no cause of death was given, a report in Variety said Horta, 45, had died by suicide.
Horta developed the hit ABC show Ugly Betty based on a Colombian telenovella.
The series charted the progress of a geeky secretary attempting to forge a career at a New York fashion magazine.
Both the show - executive produced by Salma Hayek - and its breakout star America Ferrera won Golden Globes.
"I'm stunned and heartbroken to hear the devastating news of Ugly Betty creator, Silvio Horta's death," Ferrera wrote on Instagram Tuesday.
"His talent and creativity brought me and so many others such joy & light."
Ugly Betty co-star Vanessa Williams added: "Still in shock after hearing the tragic news... His creativity and passion will be missed by so many of us that worked with him. May he Rest In Peace."
The show ran for four seasons from 2006, with Horta serving as showrunner and head writer.
Cuban-American Horta moved to Los Angeles in 1996, and sold his screenplay for slasher movie Urban Legend which became a hit film starring Jared Leto two years later.
Horta struggled to build on the success of Ugly Betty, with no major projects aired since his breakout hit ended in 2010.