Hiroyuki Nagahama (?? ??, Nagahama Hiroyuki, born 1958) is a Japanese politician of the Democratic Party of Japan (DPJ), a member of the House of Councillors in the Diet (national legislature).
A native of Tokyo and graduate of Waseda University, he was elected to the House of Representatives for the first time in 1993 as a member of Morihiro Hosokawa's Japan New Party.
After losing his seat in 1996 as a member of the New Frontier Party, he was elected again in 2000 as a member of DPJ.
In 2007, he was elected to the House of Councillors for the first time.
In 2012 Nagahama was appointed the Minister of the Environment