Short answer — these Australian-available brands explicitly offer cat foods marketed as suitable/complete for “all life stages” (i.e., labelled for kittens through seniors):

• ADVANCE (All‑Ages / Multi‑Cat formulas). (petfood.advancepet.com.au)
• Nutrience (certain Grain‑Free / canned formulas are labelled for “all life stages”). (nutrience.com)
• Talentail (offers “All Life Stages” dry cat formulas sold in Australia). (petstation.com.au)
• Trilogy (Australian brand — states it offers products and options covering all life stages). (trilogycat.com.au)
• Ivory Coat (some wet/dry products are sold as complete meals for all life stages). (ivorycoat.com.au)
• Absolute Holistic (wet/RawStew lines listed as suitable as a complete diet for cats at all life stages). (habitatpets.com.au)

Quick notes:

• “All life stages” formulas exist, but many international veterinary/nutrition brands (Royal Canin, Purina, Hill’s, etc.) instead produce separate kitten / adult / senior formulas tailored to each life stage — so those brands usually recommend choosing by age/health rather than one single “all‑ages” product. If you prefer a single diet for convenience, look for an explicit “all life stages” or “complete for all life stages” statement on the product page or bag and confirm nutrient statements. (royalcanin.com)
• Always check the product’s “complete and balanced” or AAFCO/Nutrition Statement on the label and, for kittens, pregnant or medically‑compromised cats, check with your veterinarian before using an all‑ages formula.

If you want, I can: (a) list specific all‑life‑stages SKUs from any of the brands above, (b) compare ingredient/nutrient panels for two brands, or (c show local retailers that stock them. Which would help most?