Police arrested the two at 8 a.m. AT at their respective homes following an investigation by the RCMP/Halifax Regional Police Criminal Investigation Division.
The ages of the two males arrested have not been released.
The two remain in police custody and are being questioned.
RCMP Cpl. Scott MacRae said police can hold the pair for up to 24 hours, after that they must either be charged or released.
According to Leah Parsons, Rehtaeh's mother, four boys sexually assaulted her daughter when she was 15. The Cole Harbour, N.S. teen was then said to have been mocked by classmates, enduring relentless harassment and humiliation after a photo of the attack was circulated at school and on social media.
On April 7, Rehtaeh was taken off life support after attempting to take her own life a few days earlier.
MacRae said he does not know if the two arrested are the boys identified through cell phone pictures of the alleged assault against Rehtaeh.
The arrests come one day after the implementation of new, more strict legislation against cyberbullying in Nova Scotia.
The new legislation gives victims the ability to sue alleged cyberbullies or their parents, if those accused are minors.
Leah Parsons told CBC News that police came to her house and told her of the arrests at 8:10 a.m. AT.
She said police have told her who was arrested. She said she knows the two arrested and they are "at the heart" of the incident, but added she cannot identify them.
"I felt a little bit of relief, just to say, finally — like I hope — they keep saying they want to tell their side of the story, but they have never given a statement. The police have never spoken to them in all this time. So at least, here is your chance. Tell your side of the story," she said.
Parsons said she doesn't think there is a link between today's arrests and Wednesday's cyberbullying legislation.
"Today I am feeling better," said Parsons.
"Yesterday was good news, but again, new legislation is a good step in the right direction. We need the technology to catch up so that if there is cyberbullying ... we need to be able to access that and that seems to take months."