The Cu(I) alkyne azide click reaction of 17α-ethynylestradiol and di-tert-butyl (2-azidopropane-1,3-diyl)dicarbamate afforded the novel 1,4 disubstituted 1,2,3 triazole and estrogen-based ligand 2-(4-(estradiol)-1H1,2,3-triazol-1-yl)propane-1,3-diamine, EDiolDap. Reaction of EDiolDap with Pt(II) DMSO precursors, cis- [PtCl2(DMSO)2] and cis-[Pt(CBDCA)(DMSO)2] gave the corresponding Pt(II) estrogen linked complexes [PtCl2(EDiolDap)] and [Pt(CBDCA)(EDiolDap)] respectively in good yield. Both Pt(II) estrogen linked complexes exhibited superior activity as compared to cisplatin and carboplatin in 2D culture and exhibited ca. 30 fold higher activity, in terms of IC50 values, against ER+ cancer cells (cervical, breast and ovarian) as compared to the reference ER− colon cancer line. [PtCl2(EDiolDap)] and [Pt(CBDCA)(EDiolDap)] retained their anti-tumour activity in an ovarian 3D spheroid culture model and reduced the viability of ovarian cancer cell spheroids ca. 9- fold and 5-fold better, respectively, as compared to cisplatin.