EXCLUSIVE

Jerry Doyle -- best known for his role on "Babylon 5" -- died Wednesday ... TMZ has learned.

Sources tell us ... a call was made to his Las Vegas home yesterday afternoon after he was found unresponsive. It's unclear how the political radio talk show host and actor died ... but we're told no foul play is suspected. An autopsy is pending.

Jerry starred as security officer Michael Garibaldi from 1994 to 1998 and was married to co-star Andrea Thompson from 1995 to 1997. He worked on Wall Street before going into acting.

As of late ... Jerry hosted a nationally syndicated radio talk show, "The Jerry Doyle Show."