His father was an official of the Federal government and his mother a French-born banking executive, originally from Paris.

Following his stint in journalism he worked eight years in the private sector, eight and a half months as lawyer for L'Association des commis de Genève (today part of Unia), led by Charles Beer, who'd later become a cantonal councilor.

[10] Nidegger is currently a member of the board of directors of Geneva International Airport,[11] a director of SSR Genève (television and radio broadcast),[12] member of Groupement suisse des conseils en gestion indépendants,[13] member of Fondation communale pour le développement des emplois et du tissu économique en ville de Genève – Fondetec, Genève (economic development)[14] and he is a member of the Bar Commission of Geneva.

[16] In March 2021, he was a candidate for Council of State of Geneva, but lost election to Fabienne Fischer.

[17][18] He resigned from National Council (Switzerland) on 11 May 2023 and was subsequently succeeded by Thomas Bläsi.