David Harvey is widely regarded as the father of critical geography due to his seminal work, 'Social Justice and the City', which laid the foundation for the field.

Henri Lefebvre's concept of 'the production of space' emphasizes the social and political processes that shape and are shaped by the spatial organization of society.

Edward Soja's concept of 'thirdspace' refers to spaces that are neither fully public nor fully private, and where alternative and often marginalized voices can be heard.

Milton Santos's concept of 'spatial injustice' emphasizes the unequal distribution of resources and opportunities across space, leading to social and economic disparities.

Doreen Massey's concept of 'power-geometry' emphasizes the spatial distribution of power relations and how they shape the social and political landscape.

Edward Said's work on postcolonialism and the geographies of imperialism has been influential in critical geography, highlighting the power dynamics and cultural representations that shape global relations.

Judith Butler's work on the geographies of gender and sexuality has explored the ways in which space and place are shaped by and shape gender and sexual identities.

David Roediger's work on the geographies of race and ethnicity has examined the historical and contemporary processes that shape racial and ethnic identities and inequalities.

Rosemarie Garland-Thomson's work on the geographies of disability has explored the ways in which space and place are shaped by and shape the experiences of people with disabilities.

Harriet Friedmann's work on the geographies of food and agriculture has examined the political and economic processes that shape global food systems and their social and environmental impacts.

Mike Hulme's work on the geographies of climate change has explored the social and political dimensions of climate change, including the uneven distribution of its impacts and the challenges of adaptation and mitigation.

Nancy Krieger's work on the geographies of health and well-being has examined the social and environmental factors that shape health outcomes and health inequalities.

Saskia Sassen's work on the geographies of migration and displacement has explored the global flows of people and the social, economic, and political consequences of migration.

John Urry's work on the geographies of tourism and leisure has examined the social and cultural practices associated with tourism and leisure activities and their impacts on places and communities.

Ananya Roy's work on the geographies of urban informality has explored the social, economic, and political processes that shape informal settlements and the lives of people living in them.