The arrest follows an investigation into around 245 offences of criminal damage to Northern Line trains between February 2022 and January 2026.
The man was arrested in the early hours of Friday (January 9) at an address in Barnet on suspicion of criminal damage.
He was taken to police custody for questioning and has since been released on conditional bail while inquiries continue, the force said.
BTP Superintendent John Loveless said: “This arrest is a significant moment in our ongoing investigation into the vandalism of a huge number of trains, with the cost of repairing the damage running into hundreds of thousands of pounds.
“We are committed to working with our rail partners to stamp out this destruction of rail property which has huge financial implications for the rail industry.
“Far from being a victimless crime, graffiti damage has a knock-on effect for rail users and commuters causing frustrating delays and inconvenience while trains are taken out of service to be cleaned.
“It is also extremely dangerous to access a live railway and can result in serious injury or, in some cases, death.
“Our officers carry out proactive patrols and specialised operations to target and arrest offenders, including the use of wide-reaching CCTV across the network to identify suspects.
“Investigations like this are at the forefront of BTP’s mission to tackle graffiti across the network.”
