Over the last two decades, neo-liberal education reform has notably transformed the landscape of early childhood education and care (ECEC) in Aotearoa New Zealand. From an increasingly supportive approach, aiming to ensure access to and the participation of all children in quality ECEC provision, the country has swung towards a 'hands off' approach, which allowed the market to define who provides early childhood services, to whom and how. Increasing privatisation, competition and individualisation in the sector left teachers with many challenges, such as how to secure financial sustainability in the market and yet meet needs of children, families and community. The time of rapid transformation and challenge has also created an opportunity for teachers individually and the early childhood profession collectively to re-think their understanding of the purpose of ECEC, professionalism, and ways of ‘being’ a teacher and ‘doing’ early childhood education in the contemporary context of Aotearoa New Zealand. Drawing on a framework of poststructural discursive studies and theoretical ideas of feminist poststructuralists, this thesis examines discursive constructions of teachers’ professional identities in ECEC policies and practice in Aotearoa New Zealand over the last two decades. Through an analysis of some key ECEC policy documents, and collective and individual interviews with teachers, professional leaders and managers from both community-owned and for-profit services, the study shows the shaping of complementing and opposing discourses on teachers’ work and professional identities. The thesis argues that the Aotearoa New Zealand ECEC has been torn between tensions created through an interplay of divergent and opposing discursive windows, which set a powerful context for constructions of complex and fluid teachers’ professional identities. It shows that discursive windows of enterprise, economic investment and vulnerability have promoted competition, individualism, entrepreneurship and social-intervention emphases in the sector, and frequently overpowered discourses of collectivism, collegiality, and empowerment, in which democratic education and professionalism have been rooted. Through a constant struggle to resolve tensions among the confronting and yet simultaneously coexisting interests and priorities in ECEC, teachers need to constantly re-invent their professional selves. This thesis adds to the scholarship about possible impacts of policy developments on teachers’ professional identities specifically and the teaching profession generally. By discussing some complex issues in the Aotearoa New Zealand ECEC, the study contributes to an understanding of how contemporary early childhood discourses may weaken capacity for constructing advocate-activist teachers’ identities, which are both a priority and necessity in ECEC at times when the market drives teachers’ work, requiring them to favour for-profit and enterprise interests over the wellbeing of children, families and community. However, the study also gives us some hope that discourses of democratic education, which have been strongly embedded in the New Zealand Early Childhood Curriculum Te Whāriki and the sector’s political activism, could be used as a counterbalance to the discourses which have inhibited ECEC from being a more democratic, socially just and equitable place for all citizens. As being oddly in the contrast to the increasing dominance of the privatised and market-led provision, this study suggests that the curriculum’s discourses and the discourses of political activism constitute a powerful foundation that could move teachers towards constructing advocate-activist professional identities and teaching profession in the Aotearoa New Zealand ECEC.