Lanning enjoyed a glittering international career with Australia after making her debut aged 18, and scored a century in only her second game against England.
She was made captain at 21 and would be part of a hugely successful side, winning two World Cups, five World T20s and a Commonwealth Games gold medal.
The batter has been a regular in the Women’s Big Bash League (WBBL) down under for Melbourne Stars, and at the forefront of the Women’s Premier League (WPL) in India.
Lanning was the leading run-scorer for Delhi Capitals during the inaugural 2023 season and led them to the final the following two years before switching to UP Warriorz for the current edition.
She appeared in The Hundred for London Spirit and Oval Invincibles, and will now play for Lancashire in a competition beginning late May.
“This is a hugely significant signing for Lancashire Thunder, and for the county game as a whole,” said Lancashire director of women’s cricket David Thorley.
“Meg is not only one of the finest batters of her generation, but one of the most influential leaders the women’s game has ever seen.
“Her record as Australia captain speaks for itself, and her presence will have an immediate and lasting impact on our squad and the club.”