Bernard Mongan (21), from Cluide, Corrundulla in Co Galway, was killed at 8.30pm on Monday, when his car collided with another car at Carrowhuineagh, Dunmore, Co Galway.
Two units of Tuam fire brigade attended the scene of the two-car accident, which saw four others, including a two-year-old girl, injured.
His fiancée, Chantelle McDonagh, was on a family holiday to Medjugorje when the tragic accident occurred. She is now travelling home.
"Bernard was a very, very nice guy. He was due to get married next June. We just can't take it in, we can't really believe it.
"Bernard was a big guy, a six-footer and a very, very strong guy, but he was just a gentle giant. Everybody liked Bernard."