Will wheels from a s10 fit Pontiac fiero?

No, S10 wheels will not directly fit a Pontiac Fiero. The bolt patterns (the number of lug nuts and their spacing) are different. The Fiero uses a 4x100 bolt pattern, while the S10 typically uses a 5x4.75" or 5x120.7mm bolt pattern (depending on the year and model). Even if you could somehow get the wheels to bolt on, the wheel offset would likely be significantly different, leading to clearance issues with the suspension and body.