Made of glass Perspex, the installations were unveiled at three churches including Westminster Abbey ahead of commemorations later this year to mark 100 years since the conflict's end.
The installations are a pilot scheme included in £2 million worth of funding from the Armed Forces Covenant Fund Trust - a group which supports the armed forces community - and its There But Not There campaign.
Churches, schools, community venues and places of worship which would otherwise struggle to afford a commemoration are being invited to apply for grants of up to £500 to cover the cost of installing ten glass silhouettes.
The Archbishop of Canterbury Justin Welby, who is backing the campaign, said: "I hope that many churches will want to engage with this...
"As we commemorate the end of the First World War, it is vital that we remember and this project allows us to do so in a way that will engage with the imagination and be a real exercise in remembrance."
In addition to Westminster Abbey, the glass figures also appeared at St Margaret's Church in Bodelwyddan, north Wales and in Arundel Cathedral, West Sussex.
More than 60,000 of the Perspex 'Tommies' have been sold by the Armed Forces Covenant Fund Trust, raising £1.8 million for charity.
Larger, metal-lined replicas of the models have also appeared at various locations across the UK.
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