There have been calls for Colombia to rename this year's Independence Day as "Freedom Day" for the 2,800 people held captive in remote jungle and mountain camps by both the Farc and the National Liberation army, another armed group.
The Farc has suffered a series of setbacks recently as a result of a US-backed military offensive.
Recent successes against the group have helped to increase the popularity of Alvaro Uribe, Colombia's president.
"The Farc has never been as isolated politically or militarily as it is now," Lucia Newman, Al Jazeera's correspondent in Colombia, said.
"In all of Colombia, millions of people are expected to gather to call for peace on this Independence day."
Andreas Correa, 30, a Bogota city employee said: "For the first time in my lifetime we are really starting to believe that peace is possible."
Chants of "no more kidnapping" and "freedom" were made by protesters who waved white peace flags.
Francisco Santos, the vice president, who marched in Bogota. He was kidnapped almost two decades ago by drug traffickers.
Santos said that the FARC must recognize that "its fight is over and that the only option is to sit down for talks that would mean laying down their arms.''
'No more hostages'
In Europe, several cities also saw anti-Farc rallies and Ingrid Betancourt, freed from the Farc earlier this month, appeared at a concert in France.
"No more hostages!" Betancourt chanted as she addressed a crowd of several thousand people, many of whom waved Colombian flags and chanted "Freedom, freedom".
Betancourt called for the Farc to lay down their arms and free the hundreds of hostages they still hold.
Juanes, a Colombian star, as well Miguel Bose, a Spanish singer, and Renan Luce and Michel Delpech, two French artists, were among the 30 artists performing in a square across the river Seine from the Eiffel Tower.
Betancourt, who holds Colombian and French citizenship, was rescued on July 2 by Colombian armed forces who said they tricked her captors into handing her over along with three Americans and 11 other Colombian hostages.
Following the rescue effort there were rumours that Mossad, the Israeli secret service, had been involved in the operation to free Betancourt
A Spanish newspaper on Sunday claimed that Mossad, the US and the French secret service were all involved.
"Mossad and the US and French intelligence services worked for more than a year with the Colombian authorities to develop the plan," Vanguardia, the newspaper said, citing an Israeli secret service source.