高层建筑物的普通意思是指具有较多层数高度较高的建筑，但是具体达到何种程度算作高层，不同国家有不同的规定。

联合国经济事务部在1974年国际高层建筑会议将高层建筑按高度分为四类：

日本建筑大辞典将5～6层至14～15层的建筑定为高层建筑，15层以上超高层建筑。

中国《民用建筑设计通则》（JG37—87）将住宅建筑依层数划分为：1～3层为低层；4～6层为多层；7～9层为中高层；10层及以上为高层建筑。公共建筑及综合性建筑总高度超过24米为高层，但是高度超过24米的单层建筑不算高层建筑。超过100米的民用建筑为超高层。

A tower block, high-rise, apartment tower, residential tower, apartment block, block of flats, or office tower is a tall building or structure used as a residential and/or office building. In some areas it may be referred to as an "MDU", standing for "Multi Dwelling Unit". In the United States, such a structure is referred to as an apartment building or office building, while a group of such buildings is called an apartment complex or office complex.