Interleaved ECC coding for key-value data storage devices. In one embodiment, a controller includes a memory interface including a namespace database; an ECC engine; a controller memory; and an electronic processor. The electronic processor is configured to receive a host write command, determine whether write access was setup as a key-value (KV) namespace in the namespace database and is associated with the host write command, and control the ECC engine and the memory interface to perform one or more program operations on the data in the memory using the interleaved ECC coding and based on the host write command in response to determining that the write access was setup as the KV namespace in the namespace database and the KV namespace is associated with the host write command.