Conor Ferguson will make his senior Ireland debut at the European Championships in Glasgow this week after being named in an 11-strong team.
The former European junior 50m backstroke silver medallist will compete in the same event on Friday.
The 18-year-old and Shane Ryan will be the first members of the Irish team in the pool when they contest their heats.
Bangor club-mates Jordan Sloan and David Thompson will join Ryan as part of the 4x100m freestyle relay team.
Athlone's Robbie Powell is the other member of the relay team, who will be competing together for the first time at an international meet.
American-born Ryan, who was a 100m backstroke semi-finalist at the 2016 Rio Olympics, will also race in the 100m freestyle and 100m backstroke.
Sligo's Mona McSharry will be the first Irish woman into the water when she contests the heats of the 100m breaststroke on Saturday.
Cookstown swimmer Calum Bain will aim to improve on his semi-final finish at this year's Commonwealth Games when he competes the men's 50m butterfly.
Darragh Greene, who set a new national record of 1:00.21 in the 100m breaststroke in April, could become the first Irish swimmer to break the minute mark over the distance and he will be joined in the event by team-mate Alex Murphy.
"With the European Championships almost upon us we are very excited to see how this team will feature amongst some of the best swimmers in the world, particularly as our team is a mixture of youth and experience," said Swim Ireland's national performance director Jon Rudd.
"Day one is an exciting day for us with Shane Ryan, Conor Ferguson, Darragh Greene and Alex Murphy starting their campaign as well as our men's freestyle relay.
"We believe that we have some strong relay chances alongside some quality individual athletes too."
Dingley spearheads diving squad
At the same time as the swimming championships in Glasgow, Rio Olympian Oliver Dingley will lead a three-strong Irish squad for the European Diving Championships in Edinburgh.
Dingley and Jack Ffrench will both be competing in the 1m springboard preliminaries on Tuesday, 7 August while Tanya Watson is part of the field in the women's 10m platform the following day.
Ireland Squad for European Swimming and Diving Championships
Swimming: Calum Bain, Conor Ferguson, Darragh Greene, Brendan Hyland, Niamh Kilgallen, Mona McSharry, Alex Murphy, Robert Powell, Shane Ryan, Jordan Sloan, David Thompson
Diving: Oliver Dingley, Jack Ffrench, Tanya Watson