The Floreat resident, a student at Churchlands Primary School, competed in the Under 11s age group at the event on Sunday.
Matilda (9), who took up track cycling early last year, competed in four main events – a time trial, a scratch race, a sprint and an individual pursuit.
She won gold in all of her events.
“I am delighted to have done so well in my events and while I was very nervous before each race I gave it my best shot,” she said.
“I am looking forward to continuing my track cycling.”
National Cycling Centre WA head coach Amanda O’Connor said the centre was committed to supporting girls and boys to develop a passion for cycling.
“Track cycling is a great way to do this as it offers everyone a safe space in which to develop their cycling skills and increase their fitness,” Ms O’Connor said.
The National Cycling Centre WA runs trial sessions open to children of all ages, school holiday programs and community initiatives.