"En Mal de Fleurs" (Québec, Lèvres Urbaines 30 1988) is a suite of poems written directly in French.

An English translation by Kaarina Hollo of O'Sullivan's poem "Marbhghin 1943: Glaoch ar Liombo" ("Stillborn 1943: Calling Limbo") Archived 3 February 2013 at the Wayback Machine won the 2012 Times Stephen Spender Prize for poetry translation Archived 3 May 2013 at the Wayback Machine, a competition open to poems in all languages and from all periods of history.

O'Sullivan's poem ‘Blip’ was incorporated into the fabric of the Gaelscoil (Irish-medium primary school) in Bantry, County Cork, as part of a public art project in 2014, in collaboration with the artists Cleary&Connolly [1].

Other collaborations with visual artists include "Ceamara/Camera", a bilingual Irish/English poem, reply to Jean-Max Albert’s french poem ‘’La camera sans film’’, in a hand-printed, limited-edition art book by Kate Van Houten (Estepa Editions, Paris 2010) and "Saorganach/En affranchi à faux", a bilingual French/Irish poem illustrated by Valerie Vahey Archived 29 October 2015 at the Wayback Machine in a hand-printed, limited-edition boxed set, "Poésie et Gravure" (Ateliers Bo Halbirk, 2012).

O’Sullivan was commissioned by the PayneShurvell gallery to write an interpretation of Rudolf Reiber's Suspiria (2012) as part of the first solo exhibition in London of the German artist.