Jack Merritt, 25, and Saskia Jones, 23, will be honoured in a remembrance service at Guildhall Yard, which will also be attended by London Mayor Sadiq Khan, reports the BBC.
The service will also pay tribute to those who were injured, the emergency services and members of the public who responded.
A book of condolences will be opened at Guildhall Art Gallery, and members of the public will be invited to lay flowers outside nearby Mansion House.
The service will take place, less than a mile from Fishmongers' Hall, where convicted terrorist Usman Khan, 28, carried out the attack and was later shot dead by the police.
Merritt and Jones were both University of Cambridge graduates, and had been attending an event for the varsity's Learning Together programme, which focuses on prisoner rehabilitation, when they were attacked.
Monday's vigil at Guildhall Yard follows a service for the victims on Sunday at Southwark Cathedral, which was attended by hundreds.
The Dean of Southwark Cathedral, the Very Reverend Andrew Nunn, said many people were struggling with what happened.
The attack comes after the UK's terrorism threat level was downgraded on 4 November from "severe" to "substantial", meaning that attacks were thought to be "likely" rather than "highly likely".
( With inputs from IANS )