What can I substitute for sesame oil?

If you have sesame seeds instead, you can toast them and use a neutral oil.

Peanut oil, though it isn't the same. If you are making the sub because of a sesame allergy be really, really careful, though. Most nut oils are contaminated with trace sesame seeds and you are much safer using olive and canola. I accidentally caused someone to go into shock because of contaminated peanut oil :(

Sesame oil is unique . I don't think sesame tastes like pumpkin. Maybe use peanut oil and a liberal sprinkle of sesame seed on the dish.

Pumpkin seed oil, to approximate the toasted sesame taste, should be unrefined for full flavor.

Pumpkin seed oil may make an adequate substitute, depending on what the dish is.

It really depends on what you're making - it's such a powerful, unique flavor that often really makes a dish, I don't know that there is a good replacement. Again, depending on the dish, it may be ok to leave it out though.