Plans include a new entrance and concourse on the south side of the station and more shops and restaurants on the north concourse.
There will also be improvements to the New Station Street entrance and 350 extra car parking spaces for passengers.
Work will begin on the south side of the station later this month, while plans for a new £15m entrance have already been approved by Leeds City Council for construction to be completed by 2014.
A new multi-story car park and improved short-stay and drop-off facilities are also due to be completed by mid 2014.
Richard Lungmuss, route director for Network Rail, added: “Leeds station is the gateway to the city for visitors and businesses alike. Thousands of passengers already pass through each day.
“With passenger numbers in Leeds predicted to surge by 63% by 2029, these value-for-money investments and upgrades are essential to make sure we provide the best possible station and are able to cope with future demand for rail services.”
“The new entrance, which we estimate will handle around 20% of the current station footfall, is designed to tie-in with the existing western footbridge, avoiding the cost of redeveloping the narrower, eastern footbridge.”