Ireland were meant to have played Georgia in their opening Group A game last Friday but that was rescheduled until June 2022. So their preparation this week has been centred on the 11th-highest ranked team in women's football.
Tickets are almost sold out for the game, with a capacity set at 4,000 due to COVID restrictions.
Midfielder Ruesha Littlejohn is ruled out due to a foot injury.
All of the players & staff have tested negative for COVID-19.
Republic of Ireland Manager Vera Pauw
“Australia are officially the ninth-best team in women's football and recently finished fourth at the Tokyo Olympics. We know just how good they are and this opportunity to test ourselves against such a top-class opponent is one that we are ready to make the most of.
"We have never played against Australia at senior level before so this fixture is a first in many ways. Crucially, though, it acts as another chance for us to work together as a group to be in the best position possible for our first 2023 FIFA World Cup qualifier.
"The start to our qualifying campaign has been delayed due to COVID issues in Georgia - where we faced the possibility of travelling without over 20 players - so we now have to look ahead to a double-header in October at home to Sweden and away to Finland. We know how difficult these games will be so that is why this test against Australia is so important to take positives from our performance."
Republic of Ireland captain Katie McCabe
"It's an exciting game, Australia are a top class side and it will be a great test for us. We've been playing against a lot of top quality teams of late and they certainly fall into that bracket.
"I know a few of the Australian players from my club, Arsenal, and we've been having a laugh talking about the game. But it will be down to business on Tuesday for them and for us because we want to put on a good performance.
"One of the big things about this game is that we can finally have our fans back in Tallaght after so long away due to COVID. We're fully aware of the need to maintain social distancing and the protocols in place, but there is no doubt that they will make a difference for us - they have always been fully behind us."
Republic of Ireland WNT Squad
Goalkeepers: Grace Moloney (Reading), Courtney Brosnan (Everton), Eve Badana (DLR Waves)
Defenders: Harriet Scott (Birmingham City), Niamh Fahey (Liverpool), Diane Caldwell (North Carolina Courage), Louise Quinn (Birmingham City), Claire Walsh (Glasgow City), Savannah McCarthy (Galway WFC), Áine O'Gorman (Peamount United), Isibeal Atkinson (Celtic)
Midfielders: Denise O'Sullivan (North Carolina Courage), Jamie Finn (Birmingham City), Ciara Grant (Shelbourne), Niamh Farrelly (Glasgow City), Aoibheann Clancy (Wexford Youths), Jess Ziu (Shelbourne), Katie McCabe (Arsenal)
Forwards: Heather Payne (Florida State University), Rianna Jarrett (London City Lionesses), Amber Barrett (FC Koln), Kyra Carusa (HB Hoge), Clare Shine (Glasgow City), Emily Whelan (Birmingham City), Saoirse Noonan (Shelbourne), Leanne Kiernan (Liverpool), Lucy Quinn (Birmingham City)
Goalkeepers: Lydia Williams (Arsenal), Mackenzie Arnold (West Ham United), Teagan Micah (Rosengard)
Defenders: Angela Beard (Fortuna Hjorring), Ellie Carpenter (Lyon), Steph Catley (Arsenal), Charlotte Grant (Rosengard), Emma Checker (Melbourne City), Winonah Heatly (Vaxjo), Alanna Kennedy (Manchester City)
Midfielders: Jenna McCormick (Vittsjo GIK), Jamila Rankin (Brisbane Roar), Tameka Yallop (West Ham United), Kyra Cooney-Cross (Melbourne Victory), Amy Harrison (PSV Eindhoven), Chloe Logarzo (Kansas City), Emily van Egmond (Unattached)
Forwards: Mary Fowler (Montpellier), Emily Gielnik (Aston Villa), Sam Kerr (Chelsea), Hayley Raso (Manchester City), Kyah Simon (Tottenham Hotspur), Remy Siemsen (Sydney FC)
Republic of Ireland
Goalkeepers: Grace Moloney (5 Caps / 0 Clean Sheets), Courtney Brosnan (4 Caps / 1 Clean Sheet), Eve Badana (3 Caps / 0 Clean Sheets)
Defenders: Harriet Scott (21 Caps / 0 Goals), Niamh Fahey (94 Caps / 0 Goals), Diane Caldwell (83 Caps / 3 Goals), Louise Quinn (86 Caps / 11 Goals), Claire Walsh (3 Caps / 0 Goals), Savannah McCarthy (5 Caps / 0 Goals), Áine O'Gorman (107 Caps / 13 Goals), Isibeal Atkinson (Celtic)
Midfielders: Denise O'Sullivan (84 Caps / 11 Goals), Jamie Finn (5 Caps / 0 Goals), Ciara Grant (15 Caps / 0 Goals), Niamh Farrelly (3 Caps / 0 Goals), Aoibheann Clancy (0 Caps / 0 Goals), Jess Ziu (4 Caps / 0 Goals), Katie McCabe (52 Caps / 10 Goals)
Forwards: Heather Payne (18 Caps / 1 Goal), Rianna Jarrett (15 Caps / 1 Goal), Amber Barrett (23 Caps / 3 Goals), Kyra Carusa (2 Caps / 0 Goals), Clare Shine (7 Caps / 0 Goals), Emily Whelan (5 Caps / 0 Goals), Saoirse Noonan (0 Caps / 0 Goals), Leanne Kiernan (20 Caps / 4 Goals), Lucy Quinn (0 Caps / 0 Goals)
Click here to view the Media Guide for the Republic of Ireland WNT
Katie McCabe Interview
Niamh Fahey Interview
Team-mates: Courtney Brosnan & Kyra Carusa
Guess Who? Katie McCabe & Ruesha Littlejohn
My Debut: Jamie Finn
WNT Book Club: Episode 1
Grassroots Club Coaching Clinic
Irish Courage: Denise O'Sullivan & Diane Caldwell
GET TICKETS NOW - IRELAND v AUSTRALIA
Republic of Ireland v Australia
Tuesday, September 21
LIVE on RTÉ2
Referee: Paula Brady
Game Hashtag: #IRLAUS
Team Hashtag: #COYGIG