Wolves fan Jamie Arnold, from Norton Bridge in Staffordshire, was convicted of causing racially aggravated harassment, alarm or distress by a jury in a Wolverhampton court on Wednesday.
Arnold hurled racist insults and gestures at Ferdinand while he was on pundit duty for the clash between Wolves and Manchester United at Molineux in May 2021.
Arnold was previously banned from games for three years after being found guilty of homophobic abuse aimed at referee Mike Dean as well as mimicking disability.
Former United defender Ferdinand did not see or hear the abuse that was directed at him, but told the court of his reaction after being informed: "I felt sick if I'm honest. First time I'd gone back into a stadium in a long time, it's not what you expect. I've had this before when growing up, I don't expect it in football."
Five witnesses testified that they had seen Arnold make the gesture and CCTV footage also showed him repeat it minutes later as he, according to the prosecution, told his father what he had done.
After the conviction, Ferdinand said in a statement: "Racism will only be eradicated when we all work together as a society!
"The prosecution wouldn't have been possible without all the help and support from the witnesses, Wolves fans and staff that came forward to testify in court.
"Special thank you to Police Constable Stuart Ward (Football Hate Crime Officer), my family and my team at New Era!"
A spokesman for anti-racism organisation Kick It Out said: "Kick It Out welcomes the guilty verdict handed to Arnold today. It is imperative that perpetrators of discriminatory abuse are held to account for their actions and we hope this result sends a strong statement that racism has no place in our society."
Arnold will be sentenced next month and faces a maximum of two years in prison.