Lawyers for Dr David Dao, 69, say a condition of the payout is that the "amount remain confidential".
United boss Oscar Munoz "said he was going to do the right thing and he has", Dr Dao's lawyers said.
Dr Dao was violently removed by airline law enforcement officers after refusing to give up his seat to United staff.
Video of the bleeding Vietnamese-American doctor went viral online and sparked international outrage.
The airline had asked Dr Dao to leave his seat in order to allow four United staff members to get from Chicago to Louisville, Kentucky.
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