Australia's Jessica Fox has won the World U23 K1 canoe slalom title in Penrith, a victory she's described as "really, really sweet".

After the race Fox revealed she felt more nervous before today's race than she'd ever felt before, including before the London Olympics, where she won a K1 silver medal.

Fox said last week she had unfinished business after failing to make last year's U23 and senior World Championship K1 finals.

"This is definitely a really sweet victory, revenge I think for last year," she said.