The supporters of both struggling League One clubs were protesting against their respective owners.
Just seconds before the game was about to start, hundreds of the toy pigs were thrown onto the playing surface and put kick-off back by seven minutes.
When they were finally cleared, referee Darren Handley got the game under way.
However, more pigs were thrown onto one corner of the Ricoh Arena pitch within seconds and the two teams set off down the tunnel to wait for them to be cleared again.
The sides re-emerged and the match could start in earnest - 13 minutes late.
In a tweet released shortly afterwards, the Coalition Against Roland Duchatelet CARD said: “Charlton and Coventry fans have joined forces in protest as pigs stop play at the Ricoh.”
The match finished 1-1, which saw Coventry relegated to League Two.
Before that match, Charlton fans were seen marching through the streets ahead of kick-off with placards calling for controversial chief executive Katrien Meire and owner Roland Duchaltelet to leave the club, led by the Coalition Against Roland Duchatelet (CARD) campaign.