The 22-year-old signs on the dotted line at Abbey Stadium on a two-year deal.
Speaking as part of the Cambridge announcement of the deal, Janneh suggested he felt unwanted whilst at Ashton Gate.
“I am very glad to be here,” the forward told Cambridge United club media.
“I feel like I am wanted.
“This is the best opportunity for me and I am happy to make a fresh start. I am ready and can’t wait.”
Bristol City, meanwhile, thanked the 22-year-old for his efforts whilst at the club.
The club wrote: “Everyone at City would like to thank Saikou for his efforts during his time at the club and wish him all the best for the future.”
Literally 99% of Bristol City fans should be scoring 28/28 on this Robins quiz – Can you?
Saikou Janneh joined Bristol City in 2018, but failed to make an impact and stake a claim for a place at senior level for the club.
Throughout his four years in BS3, the forward made just six senior appearances for the Robins and was sent on several loan spells.
These came at the likes of Torquay United, Newport County, and last season, Shrewsbury Town.
This is the right move for Saikou Janneh to make at this point in his career.
He has been afforded very few first team opportunities at Bristol City and if he has to go elsewhere for a shot at regular football, then so be it.
Having had a brief spell in League One last term, he should be well placed to hit the ground running at Cambridge United, too.
Indeed, it will be exciting to see how he gets on, and whether or not the step down to find regular football pays off for the 22-year-old.