Emdadur Choudhury, 26, from Spitalfields, East London, has been charged with burning poppies on 11 November 2010 during a protest in Kensington.
He was fined £50 by Woolwich Crown Court for breaching section 5 of the Public Order Act. The court found that his actions were capable of causing "harassment, harm or distress" to witnesses.
Another man, Mohammed Haque from Bethnal Green, was also originally accused of the offence but he was subsequently cleared of the charge.
The two men were part of a group of about 20 Muslim extremists, called Muslims Against Crusades, who chanted "British soldiers burn in hell" during the two minute silence at a Remembrance Day ceremony and then proceeded to burn three replica poppies.
Judge Riddle said that Choudhury's actions were "behaviour that is bound to be seen as insulting."
The prosecutor said Choudhury's behaviour went "far beyond the boundaries of legitimate protest and freedom of expression."
The judge agreed, saying that "freedom of expression is not unlimited."
Choudhury must also pay a £15 victim surcharge on top of the fine.
Read more on the story (BBC)
Find criminal solicitors in your local area (FindLaw)