What Duolingo score do you need for Mount Allison University?

The page lists the overall score and four subscore minimums together. Two of the subscore minimums sit above the overall figure, so check all five numbers on your score report. The page gives no separate validity period for Duolingo.

For comparison, the same page asks for IELTS Academic 6.5 with no band score lower than 6.

Applicants who meet the academic requirements may be offered conditional admission and enrol in the English Pathway Program, run online in the summer and fall. Completing it gives unconditional admission with no further TOEFL or IELTS test. You can also complete university-preparatory English with one of Mount Allison's language training partners.

Requirements vary by programme and change between admissions cycles. The score that binds you is the one on your Mount Allison programme page and in your offer letter, so check it there before you book a test.