Olney is a city in Young County, Texas, United States. Its population was 3,007 as of the 2020 census. On May 18, 1951, the city was devastat…Olney is a city in Young County, Texas, United States. Its population was 3,007 as of the 2020 census. On May 18, 1951, the city was devastated by a violent F4 tornado. Thomas P. Grazulis noted this tornado was a possible F5 on the Fujita scale.