Ramsay and Lott wear the fam-iliar white moustache in the poster campaign to promote the benefits of low-fat milk.
They follow singer Beyonc Knowles and actor Hugh Jackman who took part in the US version and British number-one tennis player Andy Murray and model Nell McAndrew who starred in the Scottish campaign.
Figures show there was a 1 per cent decline in milk consumption each year between 2001 and 2008, down from 1,689ml per person per week to 1,555ml.
Ramsay said: “There is a lot of love for milk in this country, but people often assume that it’s only good for kids who need a bit of calcium.
“The truth is that milk – especially low-fat milk – is fantastic-ally good for you, me and everyone.”
Lott said: “I love the long-running milk moustache campaign and am honoured to be a part of it.”
Scotland’s “White Stuff” campaign sparked a 3.4 per cent increase in milk sales.