"We are thankful for his many contributions over the past 20 years and wish him all the best on his new journey," production company Warner Horizon and ABC Entertainment said in a joint statement.
In an Instagram post Tuesday, Harrison said he has "had a truly incredible run as host of The Bachelor franchise and now I'm excited to start a new chapter."
"I'm so grateful to Bachelor Nation for all of the memories we've made together," he continued. "While my two-decade journey is wrapping up, the friendships I've made will last a lifetime."
Harrison came under fire after an "Extra" interview with the first Black "Bachelorette" Rachel Lindsay earlier this year when he was asked about past social media posts from contestant Rachael Kirkconnell, which included attending an antebellum plantation themed ball and liking a photo showing the Confederate flag.
In the February interview, Harrison defended Kirkconnell against what he called the "woke police" on social media. "We all need to have a little grace, a little understanding, a little compassion," he said.
Harrison later apologized, saying "my ignorance did damage" and he was "ashamed over how uninformed I was." He said he was stepping aside from the franchise "for a period of time" and would not be hosting the "After the Final Rose" special that followed the season finale of "The Bachelor."
In a March interview on "Good Morning America," Harrison said he planned to return to host "The Bachelor" and "The Bachelorette."
"I plan to be back and want to be back," he told Michael Strahan. "This interview is not the finish line. There is much more work to be done, and I am excited to be a part of that change."
Harrison also said he was "saddened and shocked" by how "insensitive" he was toward Lindsay in that interview. Since Harrison announced his stepping away from the franchise, Lindsay had become a target of intense harassment and had since deactivated her Instagram account.
"I stand against all forms of racism, and I am deeply sorry. I'm sorry to Rachel Lindsay, and I'm sorry to the Black community," he said. "To anyone who is throwing hate toward Rachel Lindsay, please stop. It is unacceptable."
Season 17 of "The Bachelorette" premiered Monday night on ABC with former Bachelorettes Tayshia Adams and Kaitlyn Bristowe stepping in as hosts.
Harrison's exit was first reported by Deadline.
The Associated Press contributed to this report.