Here we have developed an approach that extends triplex-directed functionalization and crosslinking from DNA tiles to DNA origami. We have shown that TFOs can target hairpin duplexes introduced at single, multiple, or almost all of the nick sites between staples within a prototypical DNA origami structure, with ~90% loading efficiency. Functionalization of origami with amine and biotin groups was achieved by attaching cargo to the 3′ of the TFO and was effective even for bulky PEG5K/20K groups. Introduction of the groups was possible during or after assembly, without disruption to the underlying origami scaffold. Most importantly, we show that the TFO (and attached groups) can be covalently crosslinked to the origami with >80% crosslinking efficiency using psoralen-5′-labelled TFOs. We show that 60-80% of the adducts formed by psoralen are bis-adducts that tie the TFO to both staple strands of the assembled hairpins, and the yield of the crosslinked products was consistent with previous studies. Directing crosslinking reactions between proximal hairpins led to the generation of "super-staples" that prevents the stochastic dissociation of the staple (and attached TFO conjugate) from the structure. Since psoralen crosslinking utilises mild UVA light, we also demonstrated that efficient crosslinking was possible using fast irradiation times (<10 secs) and a simple narrow-band LED as a light source. Compared to other crosslinking approaches, our approach is scalable, site-specific and less damaging to the structural integrity of the origami scaffold, as well as to functionalities introduced into the structure (e.g., fluorophores).