This thesis examines the cosmopolitanization of identities at the intersection of language and space. While cosmopolitanism has been touched upon in sociolinguistic studies of globalization, few studies directly attend to its inherent spatial implications. In this background, this study aims to under score a spatial-linguistic approach by integrating linguistic landscape studies, interactional sociolinguistics, and metrolingualism. Situated in Shanghai, a growing global metropolis with glamorous cosmopolitan past and ambitious international look, data of this research were mainly collected during an overall five-month ethnographic fieldwork from 2018 to 2019. Data consist of images, interviews, fieldnotes, and public discourses were qualitatively coded and triangulated in Nvivo. The study first examines the representation of Shanghai’s cosmopolitan identity in its linguistic landscape, and underlines time-space configurations of the nostalgic ‘Shanghai Modern’ and the embracing ‘global city’ chronotope in the curation of a cosmopolitan Shanghai. Then, it delves into people’s stance acts as they talk about places and people of the city. The analysis reveals that people’s place-identities in relation to the cosmopolitan Shanghai are organized through the intertwined identifications of the ‘real’ Shanghai and the ‘real’ Shanghainese which mutually implicate each other on a chronotopic level. Further, focusing on individual’s everyday metrolingual experiences and practices, discussions also under score two aspects of the lived cosmopolitan identities, i.e., the management of metrolingual diversities in order to transcend intercultural boundaries, and the organization and stylization of everyday life to achieve distinctions and differentiations. The integrated spatial-linguistic approach employed in this study illuminates cosmopolitanization of identities in Shanghai from three perspectives: cosmopolitan identity of the city, people’s place-identities in relation to the cosmopolitan Shanghai, and their cosmopolitan identities lived in everyday space. Attending to the relatively understudied subject of language and cosmopolitanism, this thesis under scores space and place as essential analytic aspects in sociolinguistic studies on cosmopolitanism.