The baby was found by a dog walker on The Mounds, off Shannon Road, King’s Norton on Thursday April 22 earlier this year.
He was found clothed and wrapped in a blanket by a dog walker and is currently “doing well”.
The initial call for information was made in April and has seen police follow more than 1,000 lines of enquiry.
A spokesman for West Midlands Police said: “The support from the public and media has been instrumental in identifying the mother.
“West Midlands Police received an overwhelming response with more than 1,000 lines of enquiry and have since been able to locate the baby’s mother.
“As stated in our public appeals, our priority was always to ensure mom was safe and supported.
“We can confirm that no further action will be taken by us and, with partners, we are ensuring that she is getting the appropriate support and care she needs.
“This is a very upsetting case, we would ask you not to speculate any further, as this is deeply distressing for those concerned.
“We would like to thank you for all your help and support in what has been a very sensitive and emotive matter for everyone including investigators who have worked tirelessly to ensure this outcome.
“We wish the baby all the best in the future.”