The couple's civil ceremony will be an intimate one, with only immediate family members present.
It will take place at 12.30pm on Tuesday in the luxury Villa Rothschild in the German town of Königstein, near the bride's home town of Frankfurt.
According to Luxemburger Wort, Prince Felix has chosen his future brother-in-law and namesake Felix Lademacher to be his witness for the civil wedding, while German heiress Claire has opted for her future sister-in-law, Princess Alexandra.
The choice of witnesses is in keeping with the intimacy of Tuesday's ceremony, which is the first of two which the couple will celebrate in their union as husband and wife. It also demonstrates the closeness between the bride and groom with their future in-laws.
Prince Felix, 29, has explained that the decision for the official ceremony to take place in Claire's home town is down to tradition.
"It is tradition that the wedding is celebrated in the country where the bride was born", says the groom, who met his wife-to-be back in 2001 when the two were studying at renowned international boarding school Beau Soleil in Villars-sur-Ollon in Switzerland.
"We want to keep this tradition, which, as I think, is a sign of respect towards the family of my future wife. Additionally, the history of Königstein is closely connected with the history of the Grand Ducal family, which enforces the symbolic nature of the choice even more."
The religious ceremony, set to take place at the weekend at the Sainte Marie-Madeleine de Saint-Maximin-la-Sainte-Baume basilica in the South of France, will be a far bigger occasion, with 350 guests expected.
Felix, Luxembourg's second-in-line to the throne, will follow in his brother Prince Guillaume's footsteps.
When he married Stephanie de Lannoy in 2012, he and his aristocratic fiancée first married in a civil ceremony attended by close family.
The following day, the couple made the occasion public, with a wonderful wedding at Luxembourg's Grand Ducal Palace.