One person died overnight after being hit by a freight train at the Channel Tunnel's Coquelles terminal, according to Eurotunnel.
On Thursday a migrant, believed to be Syrian, died after being hit by a car on a motorway close to the tunnel.
Their deaths bring to 16 the number of people killed in or near the tunnel trying to get to the UK since June.
Emergency services have not yet been able to identify the latest victim's age or sex because of the severity of their injuries.
Eurotunnel said: "Once again it is a very regrettable accident but it shows yet again the serious risks that are involved in trying to cross the Channel illegally.
"The driver of the train has now been taken into the psychological support system that Eurotunnel operates for this kind of incident and the police will be looking after all other aspects."
Eurotunnel said services from Folkestone were being delayed by about two hours.
The situation in Calais is part of a wider migrant crisis across Europe, with huge numbers of people heading north from the Mediterranean.
Several men have faced charges in recent months after allegedly walking the 31-mile (50.5km) length of the Channel Tunnel from Calais to the UK.
New security measures were introduced at the tunnel's entrance in August to cut the number intrusion attempts, which reached 2,000 per night at their peak.
Two migrants believed to be trying to reach the UK from Calais in France have been killed over the past two days.