The couple, who married in June 2018 after meeting on Channel 4's reality series The Jump, have long been fixtures of British reality television.
Matthews also used the announcement to promote his upcoming Disney+ documentary, "Breaking Spencer Matthews," which is scheduled to debut at the end of the year.
The film will follow Matthews as he attempts seven full‑distance, 140‑mile triathlons—one on each continent—within a 21‑day period, a challenge he described as "hectic, emotional, deep, dark and very funny" and said he is "very proud" of.
Williams, who entered the 2023 edition of ITV's "I'm a Celebrity… Get Me Out of Here!" as a late addition, previously appeared on the show alongside Celebs Go Dating receptionist Tom Read Wilson.
The birth of Remy adds a new chapter to the couple's public lives as they juggle family responsibilities with demanding media projects.