Sam Kerr says a desire to play in the world's best women's soccer league led to her signing a lucrative deal with English heavyweights Chelsea.

The Matildas captain has ended weeks of speculation about her club future, announcing on Wednesday she's joining Chelsea for the next two-and-a-half years on a reported $2m deal.

The 26-year-old striker is taking a three-week holiday before linking with Chelsea for the second half of the English Women's Super League (WSL) season.

'The WSL is the best league in Europe," Kerr said in a statement.

"I want team success and I don't want it to come easy.

"I feel Chelsea have been building something special over the years and I want to be a part of that. I want to lift some trophies."

Kerr has become the face of Australian women's soccer since debuting with the Matildas at the age of 15.

The dynamo played a key role in Australia's sweep of the just-completed two-game friendly series against Chile - she scored a brace in a 2-1 win in game one in Sydney last Saturday, and set-up the match-winner in a 1-0 triumph in Adelaide on Tuesday night.

Kerr had been weighing up her club future since opting against returning to Australia's domestic W-League and Perth Glory.

She had been splitting her time each year between the Glory from October to April, then the Chicago Red Stars in the United States' National Women's Soccer League from April to September.

After Tuesday night's victory in Adelaide, Kerr conceded the gruelling schedule had led to near-exhaustion.

She outlined her plans for a three-week holiday, initially in Perth to visit family and then to Bali.

"I'm really looking forward to a break," she said post-game.

"It's the first time ever I have had scheduled time off where I can go on a holiday and take care of myself.

"It's my body - obviously I have been going back and forth (between Australia and the US) - but also my mind. I have been going non-stop.

"And the Matildas have gained a whole lot of exposure in the last few years so our lives have changed dramatically.

"It will just be nice to turn off from football and enjoy myself."

Chelsea's manager Emma Hayes hailed the signing of Kerr for her club.

"She's a player that can make things happen but she's also a fantastic team player," Hayes said in a statement.

'The fact she chose Chelsea when she could have gone to any club in the world is a testament to the players and the staff here, because she saw this is the best place for her to grow and take the next step in her career."