A new Tube announcement will urge passengers to look around them to check if others might need to sit down.
Commuter Corry Shaw said she has been pushed to tears in the past when people ignored her plea to be given a seat.
Transport for London (TfL) has said it will be supporting Ms Shaw's "Look Up" campaign and will run the announcement for the next few months.
More than 4,000 people signed a petition urging TfL to introduce the announcements.
Ms Shaw has limited mobility and lives with chronic pain which means she needs a seat when travelling.
Although she uses a "Please offer me a seat" badge, she said many commuters avoid eye contact or do not take notice of others around them.
The announcement which will be played in stations and carriages is: "Please look up to see if anyone needs your seat more than you do."
TfL said 84% of passengers who use the badges have an invisible condition.
Ms Shaw said: "When I emailed TfL a month ago I never dreamed that it would lead to a real change in the public transport system, but the message seems to resonate with people and I've had support from all over the country."
Deputy Mayor of London Heidi Alexander said on Twitter that she was "delighted" by the news, while Mayor Sadiq Khan said it will help make transport in the capital "genuinely accessible for everyone".
Other social media users have also praised Ms Shaw for her campaign...
Delighted that in response to the “Look Up” campaign by @CorryShawComedy, @TfL is now making announcements asking people to “Look Up” and look out for passengers who may be in greater need of a seat. pic.twitter.com/mOjofV7Yga— Heidi Alexander (@Heidi_LDN) July 18, 2018
This means so so much to my everyday life, no one has ever offered me a seat on the tube before. This is probably about to change, thank-you @CorryShawComedy, you amazing human #LookUp https://t.co/wDX5jcj9zn— Hannah Price (@hanhanprice) July 18, 2018