The Seat Mii will be available to GoCar members to rent on an hourly basis across Dublin.
The GoCar initiative works on a pay-per-trip basis, which allows the user the freedom to access a vehicle when and as they need it.
GoCar CEO Colm Brady said: "The SEAT Mii is a fantastic addition to the GoCar fleet.
"It comes in as one of our City Cars and will be a great option for GoCar members looking to get around the city.
"They have a very high spec and provide great performance and an enjoyable driving experience."
GoCar has also announced the opening of six new GoBases in Dublin at Clontarf, Sandymount, Donnybrook, Harold's Cross and Miltown (two).
The total number of GoBases in the capital now stands at 23, with a further five in Cork.
Five of the new GoBases are located in Dublin City Corporation car parks, which are located close to public transport links.
Brady continued: "All of the locations announced today are well-serviced by public transport and cycle lanes, which fits with our aim of establishing GoCar as a viable addition to existing public transport links.
"On-demand access to vehicles will result in less vehicles being used on Irish roads and this will have a positive environmental impact in our major cities and towns.
"The SEAT Mii will not only provide a fun driving experience for our members, but it also produces low CO2 emissions so is a perfect fit for GoCar."
"As a brand, we are delighted to be behind the GoCar initiative, which is a clever alternative to car ownership [and] very much in tune with modern living," said SEAT Director Cian O'Brien.
"The Mii is the perfect car for this scheme as it is so easy to drive and it has the environmental credentials to suit the car-sharing ethos."