Nicole Kidman has filed for divorce from Keith Urban after 19 years of marriage.

Court documents lodged in Nashville on Wednesday (AEST) confirm the Academy Award winner has petitioned to end the marriage, citing "irreconcilable differences".

The move comes just one day after news broke that the Australian superstar couple had been living apart since June, as first reported by TMZ.

Sources close to Kidman, 58, told TMZ the actress is "broken-hearted" by the split, with speculation mounting in Nashville that Urban, 57, has already moved on with another woman.

"All the signs point to the fact Keith is with another woman," one insider said.

"It's all over Nashville... Let's just say, Nicole doesn't dispute that, but she's still shocked over it."

The timing of Urban's new relationship

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