Is the passive voice allowed in APA Style?

Yes, it’s perfectly valid to write sentences in the passive voice. The APA language guidelines do caution against overusing the passive voice, because it can obscure your meaning or be needlessly long-winded. For this reason, default to the active voice in most cases.

The passive voice is most useful when the point of the sentence is just to state what was done, not to emphasize who did it. For example, “The projector was mounted on the wall” is better than “James and I mounted the projector on the wall” if it’s not particularly important who mounted the projector.