Police are urgently appealing for information to find Jean Jellings, aged 84, from Wetherby.
She was last seen at her home at St James Street.
She is described as white, 5ft 4ins tall, with grey hair.
Detective inspector Mark Swift, of Leeds District CID, said: “It is out of character for this lady to go missing like this and we are very concerned for her welfare.
“We would urgently like to hear from anyone who has seen her or who has any information that could assist in tracing her.”
Extensive searches have taken place in the area, including using the police helicopter.
Anyone with any information is asked to contact the Special Operations Room at Elland Road via 101 quoting log 398 of February 20.