I mostly called them potato (tater) bugs when I was a kid, or roll-up bugs. I spent many happy hours playing with them, and to this day, will go out of my way to keep from hurting them/
When I was a kid, we called them ‘potato bugs’. Then I found out what a potato bug actually looked like, and started calling them ‘pill bugs’.
I grew up (in the Southwest) calling them “roly-polies”, but adults around me always called them “pill bugs”.
I voted for roly-poly, with pill bug and sow bug as runners up. I wonder what fluke of evolution makes them tip over so easily. Is it because their ancestors didn’t have to walk on sidewalks or smooth surfaces?
They were always slaters when I was a kid, in New Zealand (we even studied them in science class, and that’s what the teacher called them). I now call them woodlice, as it seems to be more generically understood what I’m referring to.
I just polled four twenty-somethings, three of whom grew up in the southwest and one who grew up in Michigan, and the consensus is that it’s a roly-poly, although they’ve heard it called a pill bug.
Hmm, I seem to be the only one who calls them wood bugs. I’m from Vancouver Island, I wonder if it’s a regional thing.
Used to call them rollie-pollies or bowling ball bugs.

I wonder if it’s a regional thing.
If there’s one thing this poll proves, it’s that it’s clearly a regional thing.
I’m with FloatyGimpy. That’s a wood bug where I come from. The Okanagan Valley in BC, in case you were wondering.
Where I grew up – New York – it’s a “pillbug” (I always thought it was one word, but it’s two in the OP). Here in Kansas, it’s a “roly-poly.”
Called 'em rolly-pollies as a kid. I refer to them as woodlouse now.
In England we call it a woodlouse, we do have the pill-bug millipede things here but they seem to be rare. Woodlice are everywhere. And FWIW, round here “Roly-Poly” is a type of pudding.
Northeast Ohio, with Pennsylvania Appalachian roots. We mostly call them potato bugs, or occasionally pill bugs. Most of those other names will get you a blank stare.
Carpenter, pill-bug, or woodlouse, depending on my mood, who I’m talking to, and what, specifically I’m talking about.

..
Cymothoa exigua. You’re welcome.
Yeah, the tongue thing. I am familiar.
My family moved from Pennsylvania to New York during my first grade year. I remember that in PA we’d called them something that currently eludes me and I was reeducated on the playground of No.2 school to call them roly-polies.
Some time later (perhaps even second grade) a tall, dark, and handsome nerd boy told me “that’s an isopod.”
I’m in Maryland now and I can’t remember the last time I saw one in person.

Yeah, the tongue thing. I am familiar.
Does it make talking hard? Or are you One?
Sorry for quoting the whole thing, stupid devices.

Some time later (perhaps even second grade) a tall, dark, and handsome nerd boy told me “that’s an isopod.”
Future grammarian. A bit like pointing at a human and saying, “that’s a primate.” Yes, but…
Plus, I honestly always found pill bugs to cute little… buggers. Isopod makes me think of the above linked, and makes me never want to go anywhere near the sea.