Jacqueline Ellen Last (born 31 January 1975), better known as Jackie O, is an Australian radio host and television presenter. She is best known for presenting The Hot Hits Live from LA, Hot30 Countdown, Take 40 Australia, two series of Australian Princess, and The Kyle and Jackie O Show (with co-host Kyle Sandilands).

She has also hosted celebrity prank show Surprise Surprise Gotcha and appeared on the 2007 comedy series The Nation on the Nine Network. She also was the co-host of Big Brother (alongside Kyle Sandilands) after Gretel Killeen, the original host, resigned from the series.