Martina Navratilova. Photo: wikipedia
Radwanska announced the news on Facebook and Twitter late on Monday night, after a week of speculation as to who the mystery coach would be.
''So happy to announce Martina Navratilova as the newest member of my coaching team!'' the 25-year-old enthused.
The Czech legend was one of the giants of women's tennis in the 1970s and 1980s, winning some 59 Grand Slam titles, taking in 18 in singles, 31 in doubles and 10 in mixed doubles.
She managed to win the coveted Wimbledon singles title nine times.
Navratilova will coach Radwanska together with Tomasz Wiktorowski, who has trained the Krakow-born star since 2011.
"I am really excited about this opportunity to join Agnieszka's team and work with Tomasz and it is going to be a fun challenge,'' Navratilova said.
''I was delighted when Agnieszka asked me if I would collaborate with Tomasz and I can't wait to get started."
Meanwhile, Radwanska has heaped praise on the former champion.
"She is my idol in tennis and I am honoured we will be working together.
''Her achievements speak for themselves and I hope that I can learn from all her experience.''
Radwanska is currently World No. 6 in the WTA rankings, and although she has won 14 WTA singles titles, victory in a Grand Slam tournament has so far eluded her.
Her closest brush with Grand Slam glory came in 2012, when she made it to the final of Wimbledon, but lost to US star Serena Williams.
''My goal is to win a Grand Slam, so to have someone with Martina's accomplishments in my corner is going to be hugely advantageous and give me a big boost,'' Radwanska said.
''We are originally from a similar part of the world so we share an understanding about tennis and life, which I'm sure will translate into a successful relationship.'' (nh)