Processes for the production of high purity alpha olefins from a mixture of olefins are disclosed. The processes may include: contacting propylene and a hydrocarbon mixture comprising a mixture of olefins having a carbon number n with a first metathesis catalyst to form a metathesis product comprising a beta-olefin having a carbon number n+1, an alpha-olefin having a carbon number n−1, as well as any unreacted propylene and olefins having a carbon number n. The metathesis product may be fractionated to recover a fraction comprising the beta-olefin having a carbon number n+1. Ethylene and the fraction comprising the beta-olefin having a carbon number n+1 may then be contacted with a second metathesis catalyst to form a second metathesis product comprising an alpha-olefin having a carbon number n and propylene, which may be fractionated to form a propylene fraction and a fraction comprising the alpha olefin having a carbon number n.