Walter Charles "Heinie" Jantzen (April 9, 1890 – April 1, 1948) was an American baseball player. Jantzen was born in Chicago in 1890. He began playing professional baseball in 1910 with the Vincennes Alices in the Kentucky–Illinois–Tennessee League. In 1911, he continued in the minor leagues, playing for Vincennes as well as the Cairo Egyptians. Jantzen died at age 57 in Hines, Illinois.