The 16-year-old was easily voted the best singer during last night's second live show, having also won last week's poll.
Henderson's performance of Minnie Riperton's 'Lovin' You' took in a massive 33.09% of the vote.
Chris Maloney is her nearest competition, receiving 14.66% for his cover of Heart's 'Alone', with Jahmene Douglas finishing third with 9.83%.
Jade Ellis finished in fourth place with 9.80%, with James Arthur completing the top five with 9.01%.
Kye Sones appears to be the act in the most trouble, having finished bottom of the poll with just 1.63%.
District3 and MK1 also find themselves in the bottom three, taking in 1.93% and 2.19% respectively.
Elsewhere, Rylan Clark secured 4.22% of the vote, ahead of Melanie Masson (3.79%).
Finally, Union J polled 4.90%, just below Lucy Spraggan with 4.94%.
The X Factor continues tonight at 8pm, with the results of the second public vote being revealed. Rebecca Ferguson and Taylor Swift will also perform.