He took his episcopal motto, la joie de croire (the joy of believing), from the writer Madeleine Delbrêl.

[2]On 1 February 2008, Pope Benedict XVI appointed him Bishop of Lille, allowing him to retain the personal title of archbishop.

During that year's electoral campaign he called for the rejection of the anti-immigrant rhetoric of the National Front party, particularly its "hate speech" and "aggressive vindictiveness".

[14] In November 2021, he joined a prayer service at Dunkirk for a group of migrants who died at sea attempting to cross the English Channel.

The training courses of the past did not make people sensitive to this aspect of managing sexual urges.... Clericalism ... leads to abuse of authority.

[1] On 23 May, he received his crozier from Georges Pontier, apostolic administrator of the archdiocese, outside Notre Dame Cathedral, which was closed for restoration and reconstruction.

[18] A year earlier, when his predecessor in Paris, Archbishop Michel Aupetit, dismissed his vicar general Benoist de Sinety, a prominent figure in the media who had complained of a lack of support from Aupetit while focusing on support for migrants and those most vulnerable during the COVID-19 pandemic, Ulrich assigned Sinety to a prominent Lille parish.

[17] Ulrich supports a reform of words used by the Roman Catholic catechism in the issue of homosexuality to make them more understandable by the use of contemporary language.