Jennings noted that his intended humor occasionally didn't come across that way to some readers.
In the apology, he didn't make mention of any comments in particular, but he has drawn criticism multiple times in the past for mentioning various sensitive subjects, such as the infamous photo Kathy Griffin shared of herself holding a replica of President Trump's severed head.
According to a TMZ report, Trump's son Barron, then only 11, believed the image to be real, which prompted a response from Jennings.
"Barron saw a very long necktie and a heap of expired deli meat in a dumpster," Jennings tweeted, per the New York Post. "He thought it was his dad & his little heart is breaking."
The tweet resulted in a beef with Donald Trump Jr., who mockingly called the game show contestant "a real man" for picking on a child.
"Hey, I just wanted to own up to the fact that over the years on Twitter, I've definitely tweeted some unartful and insensitive things," Jennings began in a Twitter thread on Wednesday. "Sometimes they worked as jokes in my head and I was dismayed to see how they read on screen."
The brainiac continued his apology on Wednesday and said that when he receives backlash over a particular tweet, he usually doesn't delete it so that it can "be dunked on," inspire discourse, "smart replies and even advocacy."
"Deleting them felt like whitewashing a mistake," Jennings continued. "But I think that practice may have given the impression I stand by every failed joke I've ever posted here. Not at all!"
He added: "Sometimes I said dumb things in a dumb way and I want to apologize to people who were (rightfully!) offended. It wasn't my intention to hurt anyone, but that doesn't matter: I screwed up, and I'm truly sorry."
The reality star concluded by saying that 2020 has taught people "that we should be kinder to one another," and that he's looking forward to entering the new year with that knowledge.
There are a handful of other tweets that have gotten Jennings in a bit of trouble over the years as well.
Notably, a now-deleted tweet from 2014 said, per the Post: "Nothing sadder than a hot person in a wheelchair."
Additionally, in 2015, the star made reference to the various fans of "Star Wars" that were given the opportunity to see "The Force Awakens" before it hit theaters because of their status as terminally ill.
"It can’t be a good sign that every fan who has seen the new Star Wars movie died shortly thereafter," he tweeted, again drawing ire.
Jennings is currently set to serve as the interim host for "Jeopardy!" following the death of Alex Trebek. No permanent replacement has been named.