In this chapter we explore the expression of Differential Object Marking (DOM) in monolingual and bilingual Spanish in contact with typologically different languages. We focus on how DOM patterns are expressed in bilingual and monolingual clitic doubling and dislocated structures by investigating the effect of typological differences in case marking and the effects of definiteness, animacy and thematic role. Our findings show that while definiteness, animacy and thematic structure are relevant factors in the production of DOM across bilingual groups, there are also differences in DOM frequency related to typological distinctions in the LÍ of the bilingual groups. Finally, our findings also show variability in the monolingual data of three individuals raised in a contact situation as well as the raise of topicality as a possible factor that contributes to DOM in the L2 varieties under study.