Freema Agyeman and Harriet Walters will be absent from Law & Order's eight-part seventh run due to other filming and theatre commitments.
However, the partnership between Bradley Walsh and Paul Nicholls will remain on the crime procedural.
Brenda Blethyn will reprise her lead role in Vera for the drama's third batch of two-hour stories, of which there will again be four.
Suranne Jones and Lesley Sharp return to their parts in Scott & Bailey for a third series.
Laura Mackie, ITV's head of drama commissioning, said in a statement: "We're delighted to have Law & Order: UK, Vera and Scott & Bailey back in production.
"The recommissions show that we have a really strong slate of returning series coming to ITV in the next 12 months which complements perfectly with the new drama we're commissioning."
Scott & Bailey launched with 8.2m in 2010, still the highest-rating drama series premiere since 2005's Doctor Who.
Meanwhile, Vera recorded its best ever audience of 6.1m for its 2012 finale in May, building on a fairly mediocre start.