Harry Kane and Andy Keogh fired the hosts to victory on an emotional afternoon at The Den.
Kane's first-half header and Keogh's late penalty proved enough to see off Hull on the day the Lions said farewell to club legend Barry Kitchener, who died a week ago aged 64.
A service and minutes' applause were held before the game, in which Millwall wore special white kits in memory of their former centre-half.
They then went on to stage the most fitting tribute possible with a battling display one-club 'Kitch' would have been proud of.
Kane and Keogh's goals eased Millwall's relegation fears and secured the Lions' 1,000th home league win, a milestone they had been trying to reach since their last success on Boxing Day.