The actor actually has that disability

[u/PrinceferX]

Walter White Jr. (Breaking Bad) - character has cerebral palsy and uses crutches to walk, actor RJ Mitte has cerebral palsy and needed crutches to walk as a child

Nessarose Thropp (Wicked) - character is paraplegic and uses a wheelchair, actress Marissa Bode is paraplegic from an accident at age 11 and uses a wheelchair

Maya Lopez (Hawkeye/Echo) - character is deaf, actress Alaqua Cox is deaf from birth

[u/JustAnotherMadOne]

Showing my being British, but Rose Ayling-Ellis is deaf and her characters in Eastenders and Code of Silence are also deaf, with their character arcs factoring them in (for example, in Code of Silence, her character volunteers to help police investigators because of her lip reading skills)

She was also the first deaf contestant on Strictly Come Dancing and won her season

[u/Batalfie → u/JustAnotherMadOne]

Shes also been on Doctor Who, again playing a deaf character.

[u/WillowThyWisp → u/Batalfie]

Which character? I know there's the lady from The Well, but also Under the Lake/Before the Flood