Both reality events are expected at the end of the month although no exact dates have been officially confirmed just yet by either Channel 5 or ITV.
According to reports, Big Brother has been pencilled in to finish its current run on Thursday, July 27.
If true it would make the series 53 days long, just slightly longer than last year's shortest ever series which ran for 50 days.
Celebrity Big Brother is expected to start a few days later, potentially following Big Brother by launching on a Monday, July 31.
However the final date of BBUK and Celebrity Big Brother could face stiff competition for viewers from the Love Island final.
The ITV2 series is also set to host its final the same week as Big Brother finishes after both shows kicked off the same day last month.
Love Island had been rumoured to finish its run before Big Brother on Monday, July 24 which would've left the BB final and CBB launch in the clear.
However there's some speculation that Love Island could well be extended for an extra week, the Daily Star newspaper reports.
It could mean the hit series - currently averaging 2 million viewers a night - clashing with the Celebrity Big Brother launch.
"Ruining Celebrity Big Brother launch night would be a killer blow," a source said.
When both Big Brother and Love Island kicked off last month it was the Channel 5 series that had the upper hand with slightly more viewers.
1.3 million tuned in to the BB launch show compared to 1.2 million for Love Island's third series opener.
But since then ratings for the two shows have taken very different trajectories.
Love Island has had over 2 million viewers while Big Brother has failed to get more than a million for the past three weeks.
On Friday, Love Island had 1.9 million viewers to Big Brother's 800,000.