A mate visiting from Melbourne rang me last month asking whether she really needed to hire a car just to walk a few hours in the hills east of Perth. Short answer: no, not always, but it depends heaps on which trailhead you're after and how much extra walking you're happy to do before the actual walk even starts. Getting to Perth Hills trailheads without a car is doable for a decent chunk of the popular spots, it's just not as tidy as driving yourself, and I think it's worth being upfront about that before you build a whole day plan around it.
I grew up in Fremantle, not out in the hills, but my uncle lived in Kalamunda for years and never owned a car he trusted on the freeway. He did the whole area on buses and his own legs well into his seventies, grumbling about timetables the entire time. So this isn't theoretical for me. It's a thing real people actually do, slowly, with a bit of patience.
Why this question keeps coming up
Perth Hills sits close enough to the city that people assume it's a quick train ride and a short stroll, like heading out to Fremantle on a Sunday. It isn't quite that simple. The hills trailheads are spread out, the terrain means roads wind rather than run straight, and a lot of the car parks sit a fair way from the nearest bus stop. That gap between stop and trailhead is where most people's plans fall apart.
It's also worth saying that the region wasn't built with public transport hikers as the primary audience. Most of the infrastructure, the car parks, the signage, assumes you've driven in. That's changing slowly as more day-trippers from Perth look for car-free options, but we're not there yet.
What Transperth can actually get you close to
The starting point for any car-free plan is the Transperth journey planner, and I mean that literally, not as a throwaway line. Punch in your trailhead and see what comes back before you commit to anything. Generally you're looking at a train to Midland and then a connecting bus further into the hills, or a direct bus service depending on which suburb you're aiming for.
The buses heading further out run less often on weekends, so check there timetable before you lock in plans, because missing the last one back is a genuinely annoying way to end a nice day. On weekdays services are more frequent, which suits people doing this as a half-day trip rather than a full Saturday expedition.
The walk from the nearest stop
Once you're off the bus, you're often still walking a kilometre or two before you hit an actual trail. This is where I tell people to pick trails that are forgiving about that extra distance rather than ones where the car park basically is the trailhead.
Reservoir Road works reasonably well for this because the approach itself is pleasant rather than a slog along a busy verge. You're not fighting traffic to get to the good bit, the good bit sort of starts early. It won't suit everyone, particularly if you're short on time or carrying much gear, but if you've got a full day free it's one of the more realistic car-free options in the hills.
Perth Hills Discovery Centre and Campground without wheels
The Perth Hills Discovery Centre and Campground near Mundaring is a good example of a destination that's absolutely reachable without a car, but requires you to accept a longer travel time than you'd expect. You're generally train to Midland, then bus toward Mundaring, then a walk in. It adds an hour or so to what would be a twenty-minute drive, and I won't pretend otherwise.
What you get for that extra time is actually kind of nice though. You arrive on foot already warmed up, rather than jumping straight out of an air-conditioned car into the heat, and there's something proper satisfying about covering that last stretch under your own steam. The campground itself is well set up if you're planning to stay rather than just visit for the day, which changes the maths on transport considerably since you're not racing a last bus home.
When a tour makes more sense than public transport
Honestly, for a lot of visitors, especially anyone only in Perth for a few days and wanting to see several spots in one go, the Perth Hills Explorer Private Day Tour solves the whole problem in one hit. Someone else drives, someone else knows which car parks actually connect to decent trails, and you don't lose half your day to timetables and transfers.
I'd recommend this option specifically for people trying to hit multiple trailheads in a single day, because that's nearly impossible to do well using only Transperth connections. The bus network out there is built around getting residents to Midland and back, not around stringing together three separate hill walks before lunch.
My honest take on the tourist shuttle crowd
Here's my mildly unpopular opinion, and I'll own it. A lot of visitors default straight to the big-name, heavily marketed tourist loop through the hills without realising there's a quieter version of nearly the same trip available if you're willing to do a bit more legwork yourself, literally. The famous lookout everyone photographs is fine, genuinely fine, but I reckon the quieter trail a bit further along is usually the better walk, with fewer people and a view that's arguably just as good. It's not a dramatic opinion, it's just one I've landed on after years of taking visiting friends out there and watching their reactions at both.
And look, if you're short on time or mobility isn't straightforward for you, the well-known spot exists for good reason. I'm not saying skip it. I'm saying don't assume it's automatically the best option just because it's the one that comes up first when you search.
Planning it from Perth
If you're basing yourself in the city, treat the hills as a half-day-plus-travel exercise rather than a quick dash. Check Transperth before you leave, pack more water than you think you need since shops thin out fast once you're past Midland, and have a backup plan if a connection doesn't line up. Tourism Western Australia has broader seasonal information worth a glance too, particularly around fire season closures, which can affect trail access regardless of how you got there.
My uncle's rule, which I still use, was simple: know your last bus time before you start walking, not after. It's saved more than one of his days out there, and it'll save yours too.