You Do Need power plug adapter while traveling from Dominican Republic to Cuba.

Here is Why You Need An Adapter

The outlet and plug type used in Cuba are A, B, C and L and in Dominican Republic are A, B and C. This is how they look like.

Dominican Republic

In Dominican Republic, outlets of type A, B and C are in use.

Type A

Type B

Type C

Cuba

In Cuba, outlets of type A, B, C and L are in use.

Type A

Type B

Type C

Type L