Centre Elen Evans moves to the wing from midfield while Robyn Wilkins moves out one spot to outside centre. Catrina Nicholas switches from No 8 to flanker while Nia Davies moves from the second row to the back row.
Flanker Sian Williams and winger Laurie Harries drop down to the replacements bench.
Wales head coach Rhys Edwards believes the changes he has made gives the starting line-up a more balanced outfit compared to the side that lost 11-12 to Italy on Sunday.
"It's great to welcome back Tails [Rachel Taylor] as I think we missed her leadership a bit. The three who come in all made an impact from the bench against Italy so it's good to have that strength in depth.
"The changes we've made in the forwards gives us a much better balanced pack. It's all about getting the combinations right. We've moved Nia Davies - who I thought was exceptional against Italy - back to the back row from the second row while in the backs we've brought in Rebecca [de Filippo] so Robyn [Wilkins] will play at 13."
Edwards is under no illusions as to the size of the task that awaits his squad, particularly as Ireland romped to a comfortable 59-0 victory over Scotland last weekend to get their defence of the crown off to a winning start.
"We are fully aware of what Ireland can do and where their major threats come from. We just have to concentrate on trying to nullify their threats and take our chances when they come," added Edwards.
Wales Women v Ireland
15 Dyddgu Hywel (Bristol Ladies)
14 Elen Evans (Waterloo)
13 Robyn Wilkins (Llandaff North)
12 Rebecca de Filippo (Bristol Ladies)
11 Philippa Tuttiett (Bristol Ladies)
10 Elinor Snowsill (Bristol Ladies)
9 Amy Day (Llandaff North)
1 Megan York (Blaenau Gwent)
2 Lowri Harries (Neath Athletic)
3 Catrin Edwards (Bristol Ladies)
4 Jenny Hawkins (Llandaff North)
5 Shona Powell Hughes (Neath Athletic)
6 Catrina Nicholas (Llandaff North)
7 Nia Davies (Cardiff Met)
8 Rachel Taylor (Captain) (Bristol Ladies)
16 Carys Phillips (Bristol Ladies)
17 Jenny Davies (Waterloo)
18 Caryl Thomas (Bath Ladies)
19 Sian Williams (Worcester)
20 Sioned Harries (Llandaff North)
21 Sian Moore (Bristol Ladies)
22 Laurie Harries (Llandaff North)
23 Ffion Bowen (Maesteg Celtic)