Trust us on this one. There’s a difference between these two. Distrust is a complete lack of trust, and it’s often based on experience. Mistrust is a general lack of trust or confidence, sometimes based on instinct. Both words can be used as either verbs or nouns. As adjectives, they’re distrustful and mistrustful, respectively. Distrust tends to be used far more frequently than mistrust.
Distrust tends to express a lack of trust stemming from experience or certain knowledge. So you could say, “I distrust George’s word because he’s lied to me before.”
In contrast, mistrust more often refers to a vaguer lack of trust that takes the form of unease or uncertainty. Mistrust is more likely to be based on feelings than experience. For example, “No one knew who had stolen the last cookie. There was a general air of mistrust in the apartment with all roommates suspecting each other.”
Sometimes, you’ll hear people use mistrust to describe their own feelings or doubt in their abilities. Take this sentence, for example: “The girl mistrusted her ability to finish the project on time.” A person who mistrusts herself tends to second-guess her own choices and feelings. Distrust doesn’t carry this extra shade of meaning.