The senior government minister visited the construction site of the new Kirkstall Forge station, part of a wider redevelopment of land off the A65 which will include new homes and offices.
A second new station at Apperley Bridge is due to open next week and Mr McLoughlin said the stations would bring major benefits.
He said: “I very much hope to see this station fully operational early next year and I think it is a very important development.
“There are two new stations opening in the area which will help with the connectivity between Bradford and Leeds and give opportunities to people living in those areas.”
Once the station is open, the Kirkstall Forge site will be just a six minute journey from the city centre.
West Yorkshire Combined Authority transport committee chairman Keith Wakefield said: “This is a great example of the combined authority and the city council working together on a brownfield site that will produce up to 4,000 jobs and 1,000 homes.
“This is a really big development that can only be achieved by the infrastructure we are putting in.”
Leeds City Council and the Leeds City Region Local Enterprise Partnership agreed financial guarantees with the site developers to help get the scheme underway.
The authority has also built a new road access to the former industrial site.
Coun Richard Lewis, Leeds City Council’s regeneration, transport and planning, said: “We’ve put our hands in our pockets because we knew something had to happen here because it is a brilliant site.
“I think this has the potential to do something we haven’t get anywhere else in the city.”