The long-running satirical animated show is often topical, taking aim at figures in authority.
The Guardian's Stuart Heritage called it "South Park's most furious episode ever", and noted the voiceover at the end of the show which said of the president: "His penis is teeny tiny, but his love for us is large."
Parker told the panel discussion they had received a note from the show's producers about the episode before broadcast.
"They said, 'OK, but we're gonna blur the penis,' and I said, 'No you're not gonna blur the penis,'" he explained.
The episode, shown on Paramount+, follows a merger between Paramount Global and Skydance Media being recently approved by the US Federal Communications Commission (FCC).
The merger between the independent film studio and one of Hollywood's oldest and most storied companies was first announced in 2024.
The approval came just weeks after Paramount Global agreed to pay $16m (£13.5m) to settle a legal dispute with Mr Trump over an interview it broadcast on subsidiary CBS with former Vice-President Kamala Harris.
It also follows this week's announcement by Paramount-owned CBS that The Late Show with Stephen Colbert will end in May 2026 after 33 years on air. Colbert is known for being one of Mr Trump's staunchest critics on late-night TV.