The body was discovered in undergrowth off Aldridge Road, Oscott, just before 2pm on Thursday.
West Midlands Police said the death is being treated as "unexplained" and a post mortem examination will be carried out to establish the cause of death.
A West Midlands Police spokesman said: "We’re investigating after a body was found in undergrowth near a canal off Aldridge Road, Oscott, at just before 2pm on Thursday.
"We understand the body may have been there for some time and we're working hard to carry out identification so we can inform their family.
"A post mortem examination will establish the precise cause of death which is being treated as unexplained at this time.
"Anyone who can help with our ongoing investigation should message us via live chat on our website west-midlands.police.uk quoting reference number 2103 of 11 Aug."