The DJ and professional partner Christopher Page left the competition on an Australian-themed music week of the light entertainment programme, scoring just 16 out of a possible 30 points for her paso doble.
Williams, who is engaged to musician and Australia's Got Talent judge Brian McFadden, told the official Dancing with the Stars website: "I've had so much fun and did my best to raise awareness for The Stroke Foundation [which] was my charity for the show.
"I've made so many friends from this show which is lovely as I've just moved here from Ireland, I didn't have many, so this has been great!"
Williams follows in the footsteps of previously-eliminated contestants Caine Eckstein and Erin McNaught.
Former X Factor Australia hopeful Johnny Ruffo received the joint highest score of the night, picking up 27 points and a top score of 10 from judge Todd McKenney, while daytime TV personality Kerri-Anne Kennerley had another stumble during her jive with Carmelo Pizzino, which attracted a score of 18 points.
Dancing with the Stars Australia airs on Sundays on the Seven Network.