The changes, part of the December update for the Wales and Borders network, will offer more services, strengthen connections and help boost the economy.
It launched on December 14.
Ken Skates, Cabinet Secretary for Transport and North Wales, said: “Rail connectivity is absolutely vital in driving prosperity.
“These changes will make a real difference to customers, who will benefit from more services and greater connectivity.
“This has been made possible by our £800m investment in brand-new trains for the Wales and Borders network.”
The updated timetable includes a new hourly service between Chester and Wrexham, with the number of trains on the route effectively doubled.
Other changes include an extra train each way on the Heart of Wales line between Swansea and Shrewsbury, three later last trains from Cardiff to Treherbert, Aberdare and Merthyr Tydfil, and a new hourly Sunday service on the Coryton line.
Mr Skates said: “In South Wales, people will still be able to benefit from fairer and simpler fares through TfW’s Pay As You Go (PAYG) service on these journeys.
“And of course with the beginning of the introduction of PAYG in North Wales coming soon, more and more people will get the opportunity to benefit from simpler fares.”