Li called time on her playing career at the age of 32, citing a troublesome right knee as the main factor in her decision.
During a distinguished career, the Chinese won the 2011 French Open,and reached a career-high of world number two after clinching the Australian Open title in January.
Hingis, a five-time major champion, expressed sorrow at Li's decision, particularly considering she was unable to bow out on home soil at this month's Wuhan Open.
"It's a sad day for tennis that someone like Li Na retires, because the next tournaments are in her hometown, and Beijing, and so many tournaments have moved to China," he said.
"[There has been] so much more development in the women's side on the Tour to have the tournaments there, and compared to when we started, there were little tournaments, nothing like what it is now and it's a sad day for Chinese tennis and the sport in general."
Angelique Kerber, who is currently contesting the WTA Pan Pacific Open, added: "She's a great champion and a great personality.
"She's an amazing character and I'm very happy that I could meet her because she is great. She was always funny and I think the decision is always tough to take and I wish her all the best for her new life, and I hope I will see her again."
Caroline Wozniacki, who finished runner-up at the US Open earlier this month, said Li is going to a notable absentee on the WTA Tour.
"She's a great competitor, she's been a great role model for sports in general," the Dane commented. "For tennis in Asia she's been a great representative and she's going to be missed."