Video shows the surprised audience giving him a standing ovation.
The pastor of Saint Sabina says he invited Wright because Wright is a fan of Angelou's.
Wright gave the benediction, followed by more applause, and did not speak about the Democratic presidential hopeful.
Wright had canceled several public events following an uproar over incendiary comments about the U.S. and it's historic treatment of blacks.
Obama has condemned Wright's remarks denouncing America for allegedly racist and genocidal acts.