In the morning, Prime Minister Stefan Löfven and the Social Democrat party chair Carin Jämtin placed a wreath on the grave. Former party leader Mona Sahlin was also there, and later Foreign Minister Margot Wallström arrived, and held a brief speech. She told Swedish Radio News that "it is a day for memories and political inspiration.
"I hope we will be able to keep the memory of Olof Palme alive by trying to live by his ideals and values on peace, democracy, equality and solidarity," she said.
By lunchtime, the Chilean ambassador along with a handful of other Latin American Ambassadors also paid their respects at the grave.
"Palme was quick to condemn the military coup in Chile and was a friend of Chile and Latin America," said Wallström.
Soon a sea of flowers covered the grave, which was lined by two standard bearers with the Swedish flag and the flag of the Social Democrats in Stockholm.
In the afternoon several of the people who worked closely with Olof Palme and were inspired by him were to take part in a memorial gathering at the Stockholm Culture House, which was also broadcast live on public television.
Ahead of the day, police had announced that it will open up the tip line extra this Sunday between 2 pm and 10 pm to see if any new tips may come in. The six investigators of the "Palme Group" will be manning the phones in the hope that new information will come in that could lead the investigation forward.
So far, thousands of tips have already been shared with the investigators, and many of them have been deemed as not having anything to do with finding the murderer. Over 8,000 of them have come in due to the sketch that was publicised early on in the investigation, but that today's investigators say it is "highly unlikely" that it portrays the killer.
To date, 133 people have admitted to killing Palme. The investigation continues.