During the Credits
There is an extra scene midway into the credits of Venom.
Eddie Brock (Venom) goes to San Quentin prison to do an interview with a prisoner, played by Woody Harrelson, who has the symbiote (Carnage) inside of him.
After the Credits
There is post-credits scene from the upcoming animated film, Spider-Man: Into the Spider-Verse, shown after the credits of Venom.
In the stinger, Miles stands before Peters grave, who then appears behind him. They then get chased by the police and one of the villains from the movie.
Special thanks to stevenmc8602, Random User Name, J3NN1F3R00, and James Kite for the stinger submissions!