Yes, the hub is identical
Same 5x108 PCD and same 63.4 mm centre bore: wheels from Volvo EX30 bolt on and centre on Ford Focus ST without rings. You still need to check the offset and tyres, detailed below.
≈: width estimated from the original tyre size.
Wheel by wheel: offset and tyres
Each original wheel from Volvo EX30 is compared with the one from Ford Focus ST of the same diameter: how much closer the wheel gets to the shock absorber or how far it sticks out of the wheel arch, and whether the tyre keeps the same overall diameter.
- ✓
7.5Jx18 ET46 · 225/55R18 — Fits like the original
Compared with the original 8Jx18 ET52.5 on Ford Focus ST: shock absorber side −12.9 mm, wheel arch side 0 mm, tyre diameter +10.6 % : fit it with the original tyre size of Ford Focus ST (225/40R18), not that of Volvo EX30.
Check in detail
Before fitting the wheels
An identical hub is not enough: offset, width and diameter change the position of the wheel, and larger calipers can touch a smaller wheel. Original wheels often use bolts or nuts with a specific seat: keep the fixings intended for the wheel, with the thread of Ford Focus ST (Ecrous - 12x1.50), tightened to the torque shown on its vehicle page. Finally, check that the size is among the approved fitments for your vehicle. This comparison is for guidance only: have the fitting approved by a professional.
And the other way round: wheels from Ford Focus ST on Volvo EX30?