Associated British Ports (ABP) wants to replace the 240m inner pier wall, which was built in the 1800s to help ships navigate in and out of the docks.
It said some of the inner pier was “in visibly poor condition” and needed tackling because it holds up the beach.
Swansea Council would need to approve the work, estimated at £10m to £15m.
The structure, which is currently fenced off to the public, took a hammering during the stormy winter of 2013/14, with damage caused to the high, beach-facing side of the pier.
A report commissioned by ABP, which owns Swansea docks, said the inner pier was currently safe following emergency repairs carried out between last December and July.
But it warned that “further failure is possible in the near future”, and a longer-term solution was needed.
The project would take up to eight months, with piling work restricted to autumn and winter months to avoid any impact on migrating fish.
Becky Jones, who owns the nearby Coast Cafe, said the inner pier was “not a great viewing point” at the moment, in contrast to the wider seafront.
“People come down here for a nice walk,” she told the Local Democracy Reporting Service.
“The rest of the marina is really nice. We’ve got new railings, new bars and restaurants – it’s really up and coming.”
Asked if the pier would have full public access when the work was completed, an ABP spokeswoman said: “We are currently engaging with local residents and key political stakeholders to include the development of public access and facilities.”