7:57 AM PT -- The network just released a statement about the tweet, saying, "Yesterday a tweet about the Golden Globes and Oprah Winfrey was sent by a third party agency for NBC Entertainment in real time during the broadcast. It is in reference to a joke made during the monologue and not meant to be a political statement. We have since removed the tweet."

Oprah's potential run for President is already on Trump's radar, and it's pissing him off ... Donald Trump Jr., that is.

The eldest son of POTUS is blasting NBC for gushing over Oprah Sunday night, and referring to her as "OUR future president." The network tweeted the comment shortly after Oprah's rousing speech at the Golden Globes, which aired on NBC.

Donald Jr. says, "In case anyone had any doubts about where the media stands this should take care of it. The bias against @realDonaldTrump is now so obvious they have simply given up hiding it."

Trump Jr. added, "Can you trust anything they say at this point? Americans see the truth in job #s & in their wallets!" His rant comes on the heels of Steadman Graham saying O would "absolutely" run for President in 2020, if the people convinced her.

Prez Trump has not reacted. Yet.