Cosyn may refer to:

• Edmund Cosyn
• William Cosyn, dean
• William Cosyn (MP)

• Good Bye (hide song)
• Goodbye Is Forever (song)
• Goodbye (Jason Derulo and David Guetta song)
• Goodbye (Jason Derulo & David Guetta song)
• Goodbye (Jason Derulo song)
• Goodbye Jimmy, Goodbye
• Goodbye, Jimmy, Goodbye
• Goodbye Jimmy Goodbye
• Good Bye Jonny
• Goodbye June
• Goodbye, Krabby Patty?
• Goodbye krabby patty
• Goodbye, Krabby Patty
• Goodbye Krabby Patty
• Goodbye Lady Liberty
• Goodbye Lament
• Goodbye Leonard
• Goodbye, Little Darlin'
• Goodbye Little Darlin'
• Goodbye Little Darling
• Goodbye, Little Darling
• Goodbye Little Darling, Goodbye
• Goodbye Little Darling Goodbye
• Goodbye, Little Darling, Goodbye
• Goodbye Little Darlin', Goodbye