Marwan Alshehhi (or al-Shehhi) (May 9, 1978 - September 11, 2001) was the September 11, 2001 Terrorist Attack hijacker who is accepted as having crashed United Airlines flight 175 into the World Trade Center. He trained at the Huffman Aviation pilot school with Mohammed Atta.

Alshehhi was born on May 9, 1978 in the United Arab Emirates. Alshehhi's father was a Muslim cleric, and Alshehhi was seen as a quiet and devout Muslim.

In February 1996, Alshehhi enrolled in a language institute in Bonn, Germany. Alshehhi boarded with a local family. It took two years for him to learn enough German before he enrolled in a university with a military scholarship. He spent several months in 1998 trying to pass a language exam in Hamburg, but he came back to Bonn after he failed. In Germany, all foreign students must be fluent in the German language to graduate. Alshehhi settled into Hamburg in 1999.

He left for the United States in Summer of 2001. He posed as a body guard of a "Saudi Arabian royal family member" (really Mohammed Atta) while the two of them took flying lessons in Venice, Florida. They also logged hundreds of hours on a Boeing 727 flight simulator. Alshehhi took two transatlantic trips separate from Atta.

Alshehhi is believed to have been related to Mohammed Atta. According to US authorities, he assisted in organising the attacks from within the USA. From testimony by FBI Director Mueller, Alshehhi was in charge of most of the funds, receiving money from Ali Abdul Aziz Ali and Mohammed Yousef Mohamed Alqusaidi, who may be his brother.

He was 23 years old when he is believed to have piloted the 767 into the south side of the South Tower.