I own an OM-1, and just “inhereted” some Pentax lenses from my grandfather who recently remembered he had them in a case in the basement.
But, they don’t fit on the Olympus body. Are there such things as adapters that will enable me to use the lenses, or am I out of luck? A quick google search didn’t yield anything helpful.
There are. This guy seems to have some.
There are, though sometimes you have to buy two and go to and from an intermediate semi-generic mount. They tend to be more expensive than you would wish, and you usually lose any automatic features, like aperture control or autofocus.
Unless the lenses are quite special, it probably won’t be worth the hassle and awkwardness of finding and using the adaptors. You can buy good used lenses for your camera fairly cheaply and all the functionality will work.