The phrase "beside the point" means something is irrelevant or off-topic. Antonyms for this phrase could include "central," "pertinent," "significant," and "relevant." Someone who is "beside the point" is disregarding the main topic or issue, so antonyms could also include "focused," "on-topic," "purposeful," or "attentive." Conversely, a person who is "beside the point" might also be considered "rambling," "distracting," or "diverting," so antonyms could include "concise," "clear," "simple," or "direct." Depending on the context, there could be a variety of antonyms for this phrase that accurately convey the opposite meaning of being irrelevant or off-topic.