Yes, most iPhone SE models are unlocked.
The iPhone SE can also be purchased "SIM-free". This means no carrier SIM card is included, the iPhone SE is unlocked, and a SIM card from any supported carrier can be used. One exception is Sprint or Sprint-supported carriers, which cannot be purchased using the SIM-free option. After selecting Sprint as a carrier and paying full price at checkout, the Sprint model will arrive unlocked.iPhone SE units will be locked to a carrier when a carrier installment plan or a 2-year contract is selected at checkout.