The appointments follow the recent departure of Graham Kelly, former regional creative director at OgilvyInteractive, to Saatchis Singapore in June.
According to Kelly, the pair will boost Saatchis interactive and direct marketing line up by forming a copy of the agency's interactive capabilities.
"We (Saatchis) were previously doing some good DM work, but not much interactive work, frankly. Justine and Victor will be key components in our efforts to build up that capability.
"Both of them also have experience with integrated campaigns so they will be able to contribute there as well."
Kelly said the pair's past experience would be particularly useful on the HP and Lexus accounts, given that car manufacturers are increasingly using the interactive platform. The agency also handles the Singapore Navy, Burger King, Guinness and Ricola accounts.
He noted that Saatchis did not have an interactive arm or department, and that none was planned because "if you have an agency split up along those lines, people tend to just stick within their own divisions".
"We've got very good creatives who can come up with very good ideas and we want to have those ideas translated into different media," Kelly explained.
Lee and Ong were one of OgilvyInteractive's most decorated teams. Between them, they have garnered honours from Communication Arts, One Show Interactive, New York Festivals, John Caples International Awards, the Asia Direct Marketing Awards as well as Singapore's Creative Circle Awards .
At OgilvyInteractive, they worked on the American Express, Nestle, Nokia, IBM, DHL and Pernod Ricard business.
On the decision to leave OgilvyInteractive, Ong said: "We were looking for new ground to explore and we wanted to try out a new working environment and new clients." It also helped that both Ong and Lee worked with Kelly when he was at OgilvyInteractive.