The 1991 Donnay Indoor Championships was a men's tennis tournament played on indoor carpet courts at the Forest National in Brussels, Belgium which was part of the Championship Series category of the 1990 ATP Tour. It was the 10th edition of the tournament and was held from 11 February until 17 February 1991. Fourth-seeded Guy Forget won the singles title.[1]
See main article: 1991 Donnay Indoor Championships – Singles. 
Guy Forget defeated Andrei Cherkasov, 6–3, 7–5, 3–6, 7–6
See main article: 1991 Donnay Indoor Championships – Doubles. 
Todd Woodbridge / Mark Woodforde defeated 
Libor Pimek / Michiel Schapers, 6–3, 6–0