Police said a man broke through a barrier in a auto which went onto the runway.
The news was announced by Hannover Police on Twitter, saying "An incident occurred at 15:40, after a man had broken through a gate with a auto and drove to the apron".
Take-offs and landings were suspended while the incident was investigated, though the airport's terminals remain open.
The man was quickly arrested and taken into custody.
Police cars stopped the vehicle and officers overpowered the driver.
Takeoffs and landings were halted while police experts examined the vehicle.
A Hanover police spokesperson told DW that the man in his mid-20s drove out onto the runway and followed a plane from Greece's Aegean Airlines after it had landed.
The man was believed to have acted alone.
Police have said there is no indication of a terror motive.
Police charged that the suspect had tested positive for cocaine and amphetamines, according to local media reports. The incident originally unfolded at around 1530 local time, and the airport said that flights resumed at 2006.
They couldn't give further information about where he came from because he was not carrying an identity card.
It wasn't immediately clear how long flight operations would be suspended.
Hanover Airport is an important hub in Germany offering both domestic and global flights.
Flights were delayed and diverted as a result of the incident closing the airport.