Shnaider confirmed the pair's partnership on Instagram and the world number 13 will look to build on her breakthrough 2024 season in which she won four WTA singles titles and the Paris Olympics silver medal in doubles with Mirra Andreeva.
"I'm excited to announce that Dinara Safina is joining my team as my new coach," Shnaider, 21, said on Instagram.
"The past few months, I've been searching for a partnership like this that I'm confident will be great for me both on and off the court.
"Dinara is obviously a legend, and I'm thrilled to see what we can do together."
Shnaider will play her first clay tournament of the season in Stuttgart next week.
Three-time Grand Slam runner-up Safina played her last match in 2011 and officially retired three years later after struggling with injuries.
Her foray into coaching comes shortly after her brother and fellow former world number one Safin began his partnership with Russian Andrey Rublev.
World number nine Rublev begins his preparation for the French Open, which starts on May 25, with a match against Gael Monfils in Monte Carlo later on Wednesday.