Daniel Klem Jr. is an American ornithologist, known for his pioneering research into the mortality of birds due to glass windows.

[1][2][3] He is the Sarkis Acopian Professor of Ornithology and Conservation Biology at Muhlenberg College.

[3] He served in the US military during the Vietnam War, and was awarded the Bronze Star Medal.

[3] He subsequently obtained his doctorate from Southern Illinois University.

He received an honorary doctorate from Wilkes University, where he is also a trustee.