The actress is moving into a four-bedroom home in Venice, California, which is situated next to the DJ’s property and has decided she needs a partition to keep their lives separate.
A source told RadarOnline.com: “It will give both of them some space and privacy and it will ensure neither of them can see or spy on each other!"
The troubled star left the Betty Ford Centre after a 90-day court-ordered rehab stay earlier this week and removal vans were soon seen leaving her West Hollywood apartment and heading to the Venice townhouse.
And Samantha - who had a volatile on/off relationship with the 'Mean Girls' actress from September 2008 – was quick to make her feelings known about the prospect of living near the 24-year-old beauty.
The music star – the sister of producer Mark Ronson – said: “Trust me, it wasn't planned. I'm way p***ed off right now."
Even though she has left rehab, Lindsay will still be subject to random drug and alcohol testing with a psychiatrist until a court hearing on February 24.
Read more: Lindsay Lohan leaves rehab and moves in next-door to her ex Samantha Ronson - SEE VIDEO