Halley has continued to exhibit internationally, including in New York at Mary Boone Gallery (2002, 2004, 2009, 2010, 2013); in Cologne at Jablonka Gallery (1988, 1990, 1993, 1998); in Zurich at Galerie Bruno Bischofberger (1988, 1991, 1994, 1995, 1998); in Paris at Galerie Thaddaeus Ropac (1992, 1995, 2000, 2004, 2007); in Brescia at Galleria Massimo Minini (1997, 2000, 2008, 2012); in London at Waddington Galleries (1999, 2001, 2007, 2009, 2013); and in many other cities around the world. In 2016, he staged an installation with Galerie Thomas, Munich, at Art Unlimited at Art Basel. As of 2016, Halley is represented by Greene Naftali Gallery in New York and Stuart Shave Modern Art in London.