西尔斯大厦是位于美国伊利诺州芝加哥的一幢摩天大楼，由SOM建筑设计事务所设计。楼高442米，共地上110层，地下3层，由9个22.9米见方的正方形组成。在1974年落成时曾一度是世界上最高的大楼，超越当时纽约的世界贸易中心，在被马来西亚的“国家石油公司双塔大厦”超过之前，，它保持了世界上最高建筑物25年的纪录，是当今世界最高建筑物之一。
2009年，总部在伦敦的保险经纪公司-韦莱集团，同意租用该大楼的很大比例作为办公楼，同时取得了该建筑物的命名权。
2009年7月16日10点，该建筑物官方命名正式改为韦莱大厦。
A triumph of ingenuity and innovation, Sears Tower stands tall on the Chicago skyline,constructed in 1974. It is the height of 442 meters(1,450 feet). It would keep the title of tallest building in the world until the TAIPEI 101 tower was constructed in 2004.
The building designed by Fazlur Kahn consists of nine framed tubes,which are actually nine skyscrapers on
themselves taken together into one building. The result is an interesting tower, which looks different from all angles. With comprehensive security networks and more than 3.8 million square feet of office and retall space, Sears Tower is an ideal business location in Chicago.
In March 2009 London-based insurance broker Willis Group Holdings,Ltd.,agreed to lease a large portion of the building and as part of the agreement obtained the building’s naming rights.On July 16,2009,at 10:00 am, the building was officially renamed Willis Tower.
