The building has been repeatedly shut on many weekends over the past few years due to a lack of staffing.
It means passengers have no access to the toilets, the cafe, the ticket office or a warm place to wait for trains.
Local rail campaigners say this could hit the long-term viability of the station. They fear Corby is being sacrificed to keep other local stations open. They say the Corby building is the only one affected.
The building was due to be closed all this weekend but a member of staff was found to cover today (Saturday, January 18). The building will remain closed tomorrow.
One campaigner said: “The station is being closed due to no staff available but there are lots of staff free at other local stations to cover this.
“This is happening too often when Kettering, Wellingborough and Market Harborough are never closed.
“This is the wrong direction as we are now seeing 300,000 passengers a year using Corby station.
“There will be no access to toilets or the Loco Coco cafe over the weekend. There are a lot of frustrated, angry rail users and rightly so.”
An East Midlands Railway spokesperson, said:
“We are sorry Corby ticket office has been closed occasionally in recent weeks, this is unfortunately due to staff sickness. We have made every effort to provide staff from nearby stations but this is not always possible.
"If the station building is closed, customers can still purchase or collect their tickets from the machine which is on the platform as opposed to within the station building."