According to E! News, the couple - who announced the end of their 14-month marriage back in December - have waited the required six months as stated by Californian law, meaning they are now both legally single again.
They previously reached a settlement regarding their divorce back in February, but had to wait six months until it became official, with Monday 16th July marking the final end of their marriage.
Just hours after their divorced was finalised, the Get Him To The Greek actor lashed out at Katy when filming his new TV show Brand X, describing the Wide Awake singer as an "ar*e-ache."
The Sun claims that Russell was exchanging banter with an audience member also called Katy, when he stated: "Anyway, enough of you, I’ve had enough ar*e-ache from people called Katy in the last year.”
Someone who was present at the recording then told the tabloid: "Russell was in great form, having some banter with the audience. Then he came across this audience member who was named Katy.
“They were having some chat about whether Katy could satisfy her boyfriend in bed when, all of a sudden, Russell shouted the comment about ar*e-ache. It was a blatant reference to Katy Perry."
They added: “The look on his face as he laughed after saying the comment said it all.”
Meanwhile, Perry's rumoured love interest Robert Ackroyd is reportedly planning to move from Hackney in London to Los Angeles so he can be close to the 27-year old.
Speaking of Katy's romance with the Florence + the Machine guitarist, a source told The Mirror: "Katy doesn't want to make the same mistakes she made with Russell.
"The long distance thing didn't work so if she's going to settle down again, it needs to be with someone who can be close at hand when she needs them.
They continued: "It will also take some compromising on her part. But Rob is making the move overseas towards the end of the year. It seems really sudden, but it's now or never for them.
"They've spent the majority of the past few months apart, so in one way it will actually be a test of their relationship to be around each other so much."
It is thought Ackroyd will make the move Stateside in October while taking a break from Florence Welch and Co.
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