Swiatek hired Fissette after ending a three-season partnership with fellow Pole Tomasz Wiktorowski, who helped her win four Grand Slam titles.
The 46-year-old had previously worked with former Grand Slam winners Kim Clijsters, Angelique Kerber and Naomi Osaka during his coaching career.
“I’m grateful for his support, experience, and everything we achieved together – including one of my biggest dreams in sport,” Swiatek added.
“Wim, thank you for this time and for the lessons I’ve learned thanks to you. I wish you all the best – both professionally and personally.”
Swiatek said the rest of her coaching team will remain unchanged and that she would let her fans know what’s next “at the right time”.
“I’m taking a moment to take care of myself, process this experience, and prepare for a new chapter. Simply, step by step, because as I often say – it’s a marathon, not a sprint,” she added.
While wishing her the best, Fissette noted that both he and Swiatek had aimed for more success during their partnership.
“You never know where life will take you and the ones you meet along the way. In 2018, I met Iga at the Wimbledon Champions Dinner after she won juniors. Seven years later, we won it together. A nice story,” he said on Instagram.
“We both wanted and worked for more but shared important moments and lessons. Iga, I now wish you good luck and success in what’s next. I’m sure you will have it.”