Pictures show commuters sat in dimly lit carriages suffering from power outages, before they were eventually evacuated.
Some passengers reported on social media being stuck for more than three hours while receiving no information from rail operators, while others reported being unable to go to the toilet.
National rail, Elizabeth Line and Heathrow Express services were all disrupted by the issue as the London Paddington to Reading line remained closed.
Celebrities including musician James Blunt and TV presenter Rachel Riley were also affected by the disruption.
Blunt posted on X: “Been stuck somewhere outside Paddington for close to 4 hours now. Out of peanuts and wine“.
Meanwhile Riley wrote: “Nearly 4 hours after we got on, we’re getting off the Elizabeth line, woohoo!”
A Network Rail spokesperson said the overhead cables affected were in the Ladbroke Grove area.
The spokesperson said: “We’ve had to stop all services while our engineers work as fast as they can to fix the issue. Our teams are also working with train operators to assist people on the trains affected.
“We’d urge people onboard to follow all the advice from staff while this incident is ongoing.
“Anyone planning travel tonight should check National Rail Enquiries for the latest on the disruption.”
A TfL spokesperson, said: “We’re sorry that the damage caused to Network Rail’s overhead power lines by another rail operator’s train has caused significant disruption to our Elizabeth line customers as well as all train operators out of London Paddington.
“We’re working together with response teams across partners to recover trains and get everyone home as quickly as we can.
“Network Rail are working urgently to repair the power lines and we’d encourage all customers to check before they travel over the next few days while they do this.”