new york state route 20n (ny 20n) was a state highway in central new york in the united states. it was an alternate route of u.s. route 20 (us 20) that stretched for between marcellus and cazenovia. the road began at its parent route, us 20, and ny 174 in marcellus and ended at us 20, ny 20sy, and ny 92 in cazenovia. all of ny 20n was concurrent with at least one other route, namely ny 174 in marcellus, ny 175 from marcellus to onondaga hill, ny 173 from onondaga hill to manlius, and ny 92 and ny 20sy between manlius and cazenovia. ny 20n was assigned in may 1937 and removed in 1961 along with ny 20sy.