The signing of Brunt and Sciver was today accompanied by a host of local signings, edging the Scorchers closer to a complete squad for the WBBL season ahead, with 14 of 15 places filled.
Brunt has starred with the ball for the Scorchers, claiming 26 wickets with best figures of 4-17 across the competition's first two seasons and was named the Club's inaugural WBBL Player of the Year.
"It was an easy decision to sign with the Scorchers again," Brunt said.
"I've had a fantastic time for the last two years and each year we keep getting better and better so I can't wait to get back to Perth and play with the Scorchers again.
"I've played a lot of T20 competitions but the Big Bash is special; you get to meet a lot of really great, wold class cricketers.
"I'm looking forward to having Meg Lanning with the Scorchers and I always learn a lot from Lisa Keightley."
All-rounder Sciver solidified her reputation in Australia as a big hitter by becoming the first woman to hit a six in the inaugural WBBL as a member of the Melbourne Stars.
"Hopefully I can contribute batting, bowling and fielding and I can help get some wins on the board," Sciver said.
"Katherine says the squad is young, but really fun and a great group of girls, so I'm really looking playing with the Scorchers over this Australian summer."
After a successful year with England, having claimed the World Cup on home soil, both players are looking to continue that form throughout the Big Bash season.
However, before WBBL tees off, there is the Women's Ashes and Brunt said she was particularly looking forward to the camaraderie of teammates-turned-rivals-turned-teammates Elyse Villani and Nicole Bolton.
"There's always banter with Villani and that's why we love her, but it's all fun and we are great mates with her and BoIts," Brunt said.
"I expect we'll be at their place for Christmas dinner this year.
"Hopefully, we're coming over with a lot of confidence after winning the World Cup and fingers crossed I can continue that form and play some really solid cricket."
Perth Scorchers Rebel WBBL|03 Squad: Nicole Bolton, Katherine Brunt, Meg Lanning, Elyse Villani, Megan Banting, Mathilda Carmichael, Piepa Cleary, Lauren Ebsary, Heather Graham, Mikayla Hinkley, Emma King, Chloe Piparo, Emily Smith.