马克一号（Mark I）是美国第一部大尺度自动数字电脑，被认为是第一部万用型计算机。它的生产和设计者给它起的名字是Automatic Sequence Controlled Calculator（全自动化循序控制计算机，缩写为ASCC），马克一号是它的用户哈佛大学给它起的名字。

这部机电式ASCC是由IBM的霍华德·艾肯所设计的，在1944年8月7日搬到哈佛大学。马克一号的特点为全自动运算。一但开始运算便无须人为介入。马克一号是第一部被实作出来的全自动电脑，同时与当年的其他电子式电脑相比它非常可靠。大家认为「这是现代电脑时代的开端」以及「真正的电脑时代的曙光」。

The IBM Automatic Sequence Controlled Calculator (ASCC), called Mark I by Harvard University’s staff, was a general purpose electro-mechanical computer that was used in the war effort during the last part of World War II.

The original concept was presented to IBM by Howard Aiken in November 1937. After a feasibility study by IBM’ engineers, Thomas Watson Sr. personally approved the project and its funding in February 1939.