Kateryna Handzyuk was a member of the Kherson city council and a prominent campaigner against police corruption and Russian-backed separatism.
In July the 33-year-old was attacked with sulphuric acid which left her with burns covering 40 per cent of her body.
She had remained in hospital since the attack and had undergone 11 operations in total.
From hospital she continued to post videos on social media calling for protests against corruption.
"I know I look bad now. But at least I'm being treated," she said in a video that was taken from her hospital bed.
"And I definitely know that I look much better than justice in Ukraine. Because nobody is treating it."
The exact cause of Ms Handzuk’s death is not known but local media suggests it was due to a blood clot.
Initially the attack was listed as “hooliganism” but after public outrage the case was changed to “attempted murder”.
Five people have been arrested and remain in custody in connection with the attack.
There has been an increasing number of attacks on anti-corruption campaigners in Ukraine with 55 unsolved attacks on activists since the start of 2017.
In September activist Oleg Mikhaylik was shot in the chest by an unidentified assailant in the city of Odessa.
Mr Mikhaylik was left in a critical condition and had spent the day of the shooting protesting against illegal construction on the Lanzheron Beach.
In October, a politician, Sergiy Gusovsky, was doused with an antiseptic liquid and beaten inside Kiev City Council.
Mr Gusovsky had been publicly speaking out against various investment agreements.
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