Keith Palmer, a police constable, was stabbed by the attacker, who was shot dead by police.
Ellwood, a Conservative MP and former Army officer, performed mouth-to-mouth resuscitation on Palmer in New Palace Yard, Westminster.
Four people, including the police officer and the attacker, died. At least 40 people were injured, including three other officers.
Paramedics fought to save Palmer's life, and that of his attacker, on the floor of the cobbled courtyard in front of Parliament.
His friend of 20 years, Conservative MP Adam Afriyie, told the BBC he saw him heading towards the scene despite police instructions to rush to safety.
Photographs showed the MP's bloodied hands and face as he applied pressure to the officer's wounds.
Ellwood's actions attracted admiration from his Westminster colleagues.
Conservative MP Ben Howlett tweeted: "Tobias Ellwood is an absolute hero for what he did to help the policeman this afternoon!"
Liberal Democrat leader Tim Farron said: "Today, Tobias gave MPs a good name.
The Bournemouth East MP is a Foreign Office minister, with the Middle East, Africa and counter terrorism listed among the areas within his brief.
Disclaimer: No Business Standard Journalist was involved in creation of this content
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
