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

Here is Why You Need An Adapter

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

Cuba

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

Type A

Type B

Type C

Type L

Dominican Republic

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

Type A

Type B

Type C