The front man has joined the Imps until the end of the season for an undisclosed fee.
There was increased uncertainty about the striker's future this winter, with Doncaster and Manfield both linked with his services.
But the ex-Millwall man has opted to link up with former Blues boss Michael Appleton at Sincil Bank.
He becomes Lincoln’s third January signing in the forward department, after they reportedly saw off Pompey to Swansea striker Liam Cullen last week.
They have also added Cullen’s Swans team-mate Morgan Whitaker to their ranks.
It is likely that Marquis has signed in time to feature for his new side when they take on Rotherham in League One tonight,
Marquis was brought to the south coast by Kenny Jackett for £1m in 2019, following his prolific form for Doncaster the season before.
During the 2018-19 League One campaign, he netted 26 goals in all competitions as Donny narrowly missed out on promotion.
However, he could never rediscover that form in royal blue, while often splitting opinion with the Fratton faithful.
The 29-year-old follows Ellis Harrison (permanent), Paul Downing (loan), Gassan Ahadme (permanent), and Miguel Azeez (permanent) out of the door at PO4 – opening up vital funds for Danny Cowley to use this window.
And Pompey fans won’t need to wait long for the ex-Gillingham man’s replacement, either, with Coventry City’s Tyler Walker expected to reunite with the Fratton chief in the coming days.
In total, Marquis scored 36 goals in 121 appearances during his second Pompey spell.
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