Methylamphetamine may refer to:

• Phentermine, α-methylamphetamine

• 2-Phenyl-3-aminobutane, β-methylamphetamine

Methamphetamine, N-methylamphetamine

• Methamphetamine hydrochloride, "crystal meth"

• Ortetamine, 2-methylamphetamine

• 3-Methylamphetamine

• 4-Methylamphetamine