Many who gathered for the search for Mikaeel, whose mother Rosdeep has been charged with his murder, will link along the beach at Cramond where part of the hunt was conducted by community members on Friday.
People will also gather at the foreshore in Kirkcaldy, the Fife town where police said, in the early hours of Saturday morning, Mikaeel's body had been found.
The public response has grown since the boy was reported missing and more than 1000 people a day are showing support on social network sites after his death was confirmed.
A canopy has been set up over a 100-yard long memorial site made up of flowers, soft toys and personal messages near Mikaeel's Edinburgh home.
The tributes reflect the scale of the grief felt over the death. It is hoped some of the tributes can be kept and donated to good causes.
It has also been reported as many as 2000 tributes have been laid at the site.
An Edinburgh City Council spokesman said: "We have no plans to remove the tributes at present but we will be liaising with Police Scotland as they are taking the lead on this."
The Firth of Forth tribute is expected to be held from 6.30pm to 8.30pm at Cramond Beach and Ravenscraig Beach on Friday.
The boy's mother appeared in court under her married name, Adekoya, on Monday.
Mrs Adekoya appeared in court for a private hearing that lasted a few minutes.
She made no plea or declaration and was remanded in custody and committed for further examination. She is expected to appear again in court on January 28.