Fresh from the Emerald Isle, beautiful Kathleen Mavourneen arrives at Ellis Island, where her large loving family waits to greet her. The hand of the lovely Kathleen, is soon the object of a battle between lifelong friend, Terry, a humble plumber, and smooth-talking wealthy politician Dan Moriarty. Lured by the politico's mansion and lavish lifestyle, and promised financial relief for her impoverished family, Kathleen succumbs to Moriarity's pressure and agrees to marry him. But on the night of her honeymoon, her new groom's real nature is revealed to the horrified girl, and she must question the decision that may have ruined her life.
Based on a popular all-Irish play, Kathleen Mavourneen's blend of romance, drama, and song captivated audiences for whom the Ellis Island experience was still fresh. It was filmed three times prior to this 1930 production, including a lavish 1919 version with Theda Bara in the title role. Lovely actress Sally O'Neil appeared in 49 films, her last being the 1938 remake of this very film titled Kathleen.