The Extinction Rebellion Scotland group said their action was a “citizens’ assembly”.
Around 40 people are believed to have taken part in the stunt, which the group said began by erecting a banner in the chamber declaring a climate emergency.
They said this was followed by a Burns reading, singing and a various speeches.
One activist said there had been “good action” in Scotland on climate change but much more rapid change was needed.
He said: “We’re here to ask the Parliament to take much more serious action.”
The activist added the group wants to reduce carbon emissions to net zero by 2025 to be able to fight “unsurvivable” climate change.
A Scottish Parliament spokeswoman said around 40 people booked on a public tour of the Parliament were “refusing to leave the chamber”.
She said police were called in to deal with the issue.
Police Scotland said there were no arrests in connection with the incident.
The chamber protest followed the group staging a public demonstration outside the Scottish Parliament earlier on Friday.
A Police Scotland spokeswoman said: “Police in Edinburgh have been facilitating a lawful protest in the city centre on the morning and lunchtime of Friday January 25.
“Officers were then informed by Scottish Parliament that a number of protesters were within the Parliament building and officers are in attendance with the matter ongoing.”
The protesters are understood to have left the Parliament at around 1.30pm.