The supporter managed to avoid security and ran onto the touchline to confront Howe near the end of the 2-2 draw between the clubs.
After getting into the face of the Newcastle boss, the fan was escorted away by security, and Leeds confirmed he has been arrested.
A club statement read: “Leeds United can confirm that following an incident at our Premier League match against Newcastle United today, an arrest has been made and a lifetime ban has also been issued.”
When talking to BT Sport about the incident after the game, Howe said: “That was a real surprise. I was concentrating on the game. It was the last thing you think could happen.”
He added: “I can’t repeat what he said, but it makes you think ‘what if?’
“It was personal to me. I can’t remember if he pushed me or not; it was such a strange thing to happen. Moments like that make you think. We need to be mindful of security.
“Nobody should have to feel their personal safety is violated when trying to entertain the country. I didn’t have time to be fearful, it was over in a flash. But it made me think about things after.”
Leeds took the lead in the seventh minute through captain Luke Ayling before Callum Wilson scored two penalties either side of half-time to put Newcastle ahead. Leeds managed to rescue a point late on through defender Rasmus Kristensen before Junior Firpo was sent off in stoppage time.
Leeds are still in the relegation zone but move up one spot to 18th on 31 points, one point behind Everton in 17th, while Newcastle remain third in the table on 66 points.