This article illustrates the predicaments of self-acclaimed global cities that come under pressure to decolonise heritage practices. Examining the politics of public memory in post-imperial Hamburg through the inner-city redevelopment project Hamburg HafenCity, it shows how commemorative landscapes are co-produced by market rationalities. Through document analysis and interviews with city planners, artists and campaigners, the article explores urban toponymies and heritage sites as relational and contested configurations of post-colonial memory and culture. It finds that the HafenCity’s colonial heritage premediates the area’s contemporary symbolic programme which celebrates European expansion, cosmopolitanism and Hamburg’s maritime tradition. The article engages with the multiple modes of encounter and performative responses that (neo-)colonial memory landscapes elicit. It redraws the affective geographies of (un-)belonging in a post-imperial city and charts decolonial propositions of civil society actors.