The National Transport Authority has approved public transport fare increases of between 1% and 28%.
Customers of Bus Éireann, Iarnród Éireann and the Luas will see monthly fares increase from Saturday.
Those who buy cash tickets will see the fares increase from 1 December. No Dublin Bus fares will rise until 1 December.
Bus Éireann regional city commuter tickets will increase by up to 9% for adults and 5% for children.
Those who use Leap will see the cost of their journeys remain the same, or even drop in some cases.
Bus Éireann offers Leap fares in the Eastern Region, the greater Cork area and Galway city.
It expects to roll out Leap to Limerick city and Waterford city in 2015.
Adult, student and child tickets on Bus Éireann will generally rise by between 2.5% and 5%.
People who use cash to pay for Luas journeys will face a rise of between 5.9% and 3.4% for off-peak journeys.
They will pay an extra 10c on each occasion they use the Luas.
Those who use Leap cards will see their off-peak fares drop by between 2.1% and 4.1%.
Adults who use cash to pay for all day-return tickets will see prices rise by 20c. Prepaid fares for one-, seven- and 30-day tickets will all rise by up to 7.7%.
Included among the increases are ticket price rises in excess of what the company actually sought.
For example, the adult, 30-day ticket will rise from €87 to €93 when the increase actually sought was to €91.
From 1 November, the fare for monthly and annual tickets on Dublin Bus will be increased by up to 9.17%.
From 1 December, the fare for cash, Leap and pre-paid tickets will rise, with a 6% increase on cash fares, 4% increase on Leap fares and 7% increase on pre-paid fares.
Those who live within the greater Dublin area will see their Iarnród Éireann short-hop zone fares rising by up to 28.4%.
For example, the adult three-day ticket currently costs €8.80.
Iarnród Éireann had sought to bring that up to €9.50, an 8% increase.
However, what was approved was an increase of nearly 30%, bringing the fare to €11.30.
The seven-day adult ticket will rise by over 25%, to €18.70.
Intercity fares will also rise, by between 1% and 7%.
Those who purchase weekly and day return tickets will see price increases of over 7%.
Those who use cash to pay for using the railway system in the Cork Commuter Zone will see price increases of up to 17.1%.
The Cork, Cobh, and Midleton services will see price rises by up to 9.6%.
The chief executive of the National Transport Authority has said it is putting up fares on public transport to ensure that services can be maintained.
Gerry Murphy said fares were going up because costs were increasing.
Speaking on RTÉ's News At One, he said the Government subvention, although it had stabilised this year, was cut significantly during the economic crisis.
Referring to the simplification of fares and increased savings for using a Leap card, Mr Murphy said the NTA was trying to encourage people to use Leap.
He said that Leap card users currently enjoy considerably lower fares than people paying with cash.
With Leap daily and weekly caps staying unchanged for 2015, he said Leap will soon be better value in many cases for the customer than buying a pre-paid weekly.
For Dublin Bus customers, the eight adult cash fares and eight Leap fares will be reduced to five adult cash fares and four different Leap fares.
Dublin Bus carries almost 50% of all public transport passengers in the country.
In a statement, Mr Murphy added: "With over 750,000 Leap Cards now in circulation and almost €2 million per week used in travel credit, the Leap card has clearly been welcomed by the travelling public - both for the convenience and for the value it offers."
"In fact, even with the fares increases announced today - a Leap card fare in 2015 will nearly always be the same as or lower than a cash fare was in 2012," he added.
Those who use Leap cards for Luas journeys will see their off-peak fares drop by between 2.1% and 4.1%.
The Consumers' Association of Ireland has said that there's little consumers can do to escape today's increases announced by the National Transport Authority.
Policy Advisor with the Association, Dermot Jewell told RTÉ's Six One that cash customers will be hardest hit, but he acknowledged that the company's Leap card system is a money-saver.
He said, however, the Leap card requires commuters to "front-load" to pay upfront in advance, providing credit for the company.
Dermot Jewell criticised the time-scale for the implementation of some of the increases, with some coming into effect as early as this Saturday.
