The match marked the first appearance of new Hull signing Danny Graham, but in a largely uninspiring contest at the Estadio Municipal in Albufeira, Steve Bruce's side were unable to break down their Championship opponents and had to be content with a draw.
Graham was brought on by Bruce for the final 30 minutes of the match.
Hull enjoyed the greater possession, but it was Wednesday who came closest to a goal in the first half when Jermaine Johnson saw his effort cleared off the line by Alex Bruce after he had rounded Hull 'keeper Allan McGregor.
Hull striker Matty Fryatt was denied a chance to score 10 minutes into the second half, when George Boyd played him in with a tremendous ball and he was brought down by Kamil Zayatte.
Fryatt's appeals for a free kick were ignored by the referee, and Bruce's men rarely threatened again.
Hull next meet Portuguese side Braga on Tuesday, while the Sheffield club will meet Glasgow Rangers at home on Wednesday.