A PTI spokesman made an announcement on Imran Khan’s official Facebook page. Ms Khan also confirmed on Twitter that they had decided to part ways.
The pair got married in January at Mr Khan’s home.
The former cricketer was previously married to British journalist and activist Jemima Goldsmith.
PTI spokesman Naeem Ul Haque asked for the media to “refrain from any speculation” due to the sensitivity and seriously of “this extremely painful matter”.
“There will be no further communication in this respect,” he added.
Reham Khan, a journalist, said on Twitter: “We have decided to part ways and file for divorce.”
Last year Imran Khan was at the helm of major protests and rallies calling for political reform and for Pakistani Prime Minister Nawaz Sharif to step down.