Each 2019–20 squad featured 15 active players, with an allowance of up to five marquee signings including a maximum of three from overseas. Australian marquees are players who held a national women's team contract at the time of signing for their WBBL|05 team.[1]
Several personnel changes were made before and during the season, including:
Elyse Villani, inaugural member and former captain of the Scorchers, moved back to her home state to play for the Melbourne Stars.[2][3]
Overseas marquee Nat Sciver returned to the Scorchers after not partaking in the previous season, replacing England teammate Kate Cross.[4]
Ireland marquee Kim Garth, appearing in the league for the first time since winning a second championship with the Sydney Sixers, was announced as Perth's final overseas signing for the season.[7]
On 30 October, Lisa Keightley was appointed as head coach of the English women's team, though she would continue in her role at the Scorchers until the end of WBBL|05.[8]
On 11 November, the Scorchers announced the addition of Amy Edgar to the squad as a local replacement player for Piepa Cleary who was ruled out for the remainder of the tournament due to a fractured leg sustained a week earlier while fielding during a 20-run loss at the WACA.[9]
Overseas marquees Nat Sciver and Amy Jones would become unavailable towards the end of the season due to national team commitments, prompting calls from recently appointed CA Board member Mel Jones for greater cooperation between nations and better planning on scheduling.[10][11]