Radwańska began the year at the WTA Auckland Open where as the fourth seed, she defeated Beatriz Haddad Maia and Taylor Townsend but lost to qualifier Sachia Vickery in the quarterfinal.
She then competed at the Apia International Sydney, overpowering the defending champion Johanna Konta and Catherine Bellis to advance to the quarterfinal, where she lost to Camila Giorgi.
This loss caused Radwańska to fall out of the top 30 for the first time since 2007 since she was unable to defend her finalist points at the tournament.

Radwańska was seeded 26th at the Australian Open.
She reached the third round, after defeating Kristýna Plíšková and Lesia Tsurenko, but lost to  Hsieh Su-wei, who beat Garbiñe Muguruza in the second round.

Radwańska made it three three-set victories in a row over Mona Barthel to make a winning start to her Qatar Total Open campaign.
She ultimately needed 10 match points, but avoided the tiebreak and finally closed out the match after two hours and 26 minutes. "
I’d rather not talk about those ten match points!"
Radwańska joked. "
The important thing is I won the tenth one".
In the second round, Radwańska lost to the eventual champion Petra Kvitová in three sets.

At Dubai, Radwańska lost to eventual finalist Daria Kasatkina in the opening round.
Her next tournament was the BNP Paribas Open where she received a bye into the second round.
In the second round she lost to the eventual champion Naomi Osaka, who defeated unseeded Maria Sharapova in her opening match.

At Miami Open Radwańska made a promising start, defeating world No.
1 Simona Halep in three sets.
This victory marked Radwanska's second career win over a world No.
1, and the first since 2012.
She extended her great record in Miami, too; reaching the round of 16 or better in ten of her 12 appearances.
Radwańska ended her run in Miami with a loss to Victoria Azarenka in the fourth round.
After Miami, she was promoted from 32nd to 30th in the WTA ranking.

Radwanska opened her clay-court season in Istanbul where she retired in the first round match to Donna Vekic.
It was later revealed that Radwanska hurt her back the day before during a training session.
Subsequently, she withdrew from the Mutua Madrid Open and French Open due to a back injury.

Radwańska made a winning return from injury against Timea Babos in the first round of the Nature Valley International.
Despite missing a Grand Slam for the first time in over a decade, dating back to the 2006 French Open, the former world No.
2 looked as though she'd never left over the course of 66 minutes on the Eastbourne lawns.
Radwańska, unseeded in Eastbourne, defeated No.
15 seed Daria Gavrilova to face Petra Kvitová in the third round.
Since Petra Kvitová withdrew with a hamstring injury Radwańska automatically advanced to the quarterfinal where she defeated Jelena Ostapenko to reach the semifinal.
In the semifinal she lost to Aryna Sabalenka in three sets.

At Wimbledon Radwańska defeated Elena-Gabriela Ruse in a close three-set match, saving six match points and reeling off the last three games in a row to book her place in the second round.
In the 2nd round she played Lucie Safarova, to whom she lost in straight sets.

For the first time in her career Radwańska lost to Karolina Pliskova in the first round of the 2018 Western & Southern Open, bringing their head to head to 7-1 against the Czech.
Next she played at the Connecticut Open where she lost to Petra Kvitová in the opening round.

For the first time in over a decade Radwańska came into a Grand Slam main draw outside the Top 32 seeds.
Unseeded at the US Open she lost to Tatjana Maria in first round.

Radwańska progressed to the second round of the Korea Open thanks to a two set victory over Bethanie Mattek-Sands.
In a clash of two former winners of the Korea Open, 2013 champion Agnieszka Radwańska lost to the 2015 champion Irina-Camelia Begu in the second round.

Due to her ongoing struggles with injuries Radwańska withdrew from the China Open tournament in Beijing thus ending the season early with a 14-14 singles record.
By the end of the season
Radwańska began the year at the WTA Auckland Open where as the fourth seed, she defeated Beatriz Haddad Maia and Taylor Townsend but lost to qualifier Sachia Vickery in the quarterfinal. She then competed at the Apia International Sydney, overpowering the defending champion Johanna Konta and Catherine Bellis to advance to the quarterfinal, where she lost to Camila Giorgi. This loss caused Radwańska to fall out of the top 30 for the first time since 2007 since she was unable to defend her finalist points at the tournament.
Radwańska was seeded 26th at the Australian Open. She reached the third round, after defeating Kristýna Plíšková and Lesia Tsurenko, but lost to  Hsieh Su-wei, who beat Garbiñe Muguruza in the second round.
Radwańska made it three three-set victories in a row over Mona Barthel to make a winning start to her Qatar Total Open campaign. She ultimately needed 10 match points, but avoided the tiebreak and finally closed out the match after two hours and 26 minutes. "I’d rather not talk about those ten match points!" Radwańska joked. "The important thing is I won the tenth one". In the second round, Radwańska lost to the eventual champion Petra Kvitová in three sets.
At Dubai, Radwańska lost to eventual finalist Daria Kasatkina in the opening round. Her next tournament was the BNP Paribas Open where she received a bye into the second round. In the second round she lost to the eventual champion Naomi Osaka, who defeated unseeded Maria Sharapova in her opening match.
At Miami Open Radwańska made a promising start, defeating world No. 1 Simona Halep in three sets. This victory marked Radwanska's second career win over a world No. 1, and the first since 2012. She extended her great record in Miami, too; reaching the round of 16 or better in ten of her 12 appearances. Radwańska ended her run in Miami with a loss to Victoria Azarenka in the fourth round. After Miami, she was promoted from 32nd to 30th in the WTA ranking.
Radwanska opened her clay-court season in Istanbul where she retired in the first round match to Donna Vekic. It was later revealed that Radwanska hurt her back the day before during a training session. Subsequently, she withdrew from the Mutua Madrid Open and French Open due to a back injury.
Radwańska made a winning return from injury against Timea Babos in the first round of the Nature Valley International. Despite missing a Grand Slam for the first time in over a decade, dating back to the 2006 French Open, the former world No. 2 looked as though she'd never left over the course of 66 minutes on the Eastbourne lawns. Radwańska, unseeded in Eastbourne, defeated No. 15 seed Daria Gavrilova to face Petra Kvitová in the third round. Since Petra Kvitová withdrew with a hamstring injury Radwańska automatically advanced to the quarterfinal where she defeated Jelena Ostapenko to reach the semifinal. In the semifinal she lost to Aryna Sabalenka in three sets.
At Wimbledon Radwańska defeated Elena-Gabriela Ruse in a close three-set match, saving six match points and reeling off the last three games in a row to book her place in the second round. In the 2nd round she played Lucie Safarova, to whom she lost in straight sets.
For the first time in her career Radwańska lost to Karolina Pliskova in the first round of the 2018 Western & Southern Open, bringing their head to head to 7-1 against the Czech. Next she played at the Connecticut Open where she lost to Petra Kvitová in the opening round.
For the first time in over a decade Radwańska came into a Grand Slam main draw outside the Top 32 seeds. Unseeded at the US Open she lost to Tatjana Maria in first round.
Radwańska progressed to the second round of the Korea Open thanks to a two set victory over Bethanie Mattek-Sands. In a clash of two former winners of the Korea Open, 2013 champion Agnieszka Radwańska lost to the 2015 champion Irina-Camelia Begu in the second round.
Due to her ongoing struggles with injuries Radwańska withdrew from the China Open tournament in Beijing thus ending the season early with a 14-14 singles record. By the end of the season 
Agnieszka Radwańska