A large presence of emergency services has been observed in the area as they are currently dealing with the incident.
The news was confirmed by the Thameslink rail service shortly after 3:30 p.m.
Read more: London Colney pub closes for three days after staff were ‘nutted’ by the NHS app
All lines were blocked between the two stations while emergency services dealt with the incident, but some were recently cleared.
Those whose journeys are still impacted can use many other services while the lines are blocked.
Enter your zip code below for the latest traffic and travel updates in your area:
A rail shuttle service now runs between Luton and Bedford and trip planners are being updated.
Members of the public are encouraged to check their routes before heading to a train station.
Tickets are also accepted at no additional cost on the London Underground, London buses, UNO buses (lines 602 and 653) and the Metroline (line 84).
A Thameslink spokesperson said: “It is with great sadness that we report that a person has been struck by a train between St Albans and Luton.
Another statement read: “Certain lines can now be used between St Albans and Luton.
“We expect a number of delays and service cancellations, so you may still need to use an alternate route. A rail shuttle service runs between Luton and Bedford. “
Want the latest Herts news delivered straight to your inbox? Register here.