The 15-player group also sees a return for Conor Olphert and Craig Young, who were both absent for last month's 3-2 series win over Afghanistan at Stormont as they recovered from injury.
Simi Singh retains his spot having replaced McBrine for the final two matches of that series.
Graham Hume is another player who was involved against Afghanistan that misses out this time.
The World Cup, which will be Ireland's first major tournament under head coach Heinrich Malan, gets under way on October 16.
Andrew White, chair of national men's selectors, said in a statement from Cricket Ireland: "It's an exciting time for Irish cricket as we embark on another major global tournament.
"Over the last year we have been building a solid core squad, while creating more depth in our T20 cricket. I think fans have started to see the positive strides the players have been making in this format - especially with the series win over Afghanistan - and we hope we can take this momentum into the tournament in Australia.
"Our belief is that this T20 World Cup is not an end point but the beginning of a new era. The age profile of this squad makes our future prospects very exciting, and after a season of eye-catching performances we have seen a greater level of interest in our players by teams in franchise tournaments around the world, which is a positive sign.
"One of the most considered decisions we had to make was around our spin bowling options. With George Dockrell and Gareth Delany both having an impact this summer and the variation they bring to the attack, it came down to making a choice between Simi Singh and Andy McBrine.
"Andy can feel very unfortunate to have missed out this time, but we believe Simi offers more variation on Australian wickets with his ability to take the ball away from both right and left handers.
"We believe this is one of the strongest T20 squads we have sent to a World Cup and wish the team and coaching staff well for the tournament ahead."
Ireland are set to depart for Australia on September 29 and will travel to Sydney for three warm-up matches hosted by Randwick Petersham Cricket Club.
They will then play two official warm-up matches in Melbourne against Namibia and Sri Lanka, before moving on to Hobart, where they open their first-round matches by facing Zimbabwe on October 17. The other teams in Group A are Scotland and West Indies.
Ireland squad: Andrew Balbirnie (captain), Paul Stirling (vice-captain), Mark Adair, Curtis Campher, Gareth Delany, George Dockrell, Stephen Doheny, Fionn Hand, Josh Little, Barry McCarthy, Conor Olphert, Simi Singh, Harry Tector, Lorcan Tucker, Craig Young.