TCDD

TCDD may refer to any of the following:


 * Turkish State Railways (Türkiye Cumhuriyeti Devlet Demiryolları) - The national railway carrier of Turkey.
 * TCDD Taşımacılık - A Turkish transport company responsible for railway operations.
 * 2,3,7,8-Tetrachlorodibenzodioxin &mdash; a type of dioxin.
 * Texas Council for Developmental Disabilities