Horner said it was "unfair" to boo Vettel, who has suffered repeated ill-treatment this year and was again subjected to loud chants and heckles after winning Sunday's Singapore Grand Prix.
The 26-year-old star did his best to shrug off the jeers but Horner said the booing, blamed on a particular group of fans, might be getting under his skin.
"There is a small collective group and it is like a pantomime, but it is so unfair because it is not sporting," said Horner, according to Autosport.Com.
"He is a great kid. He has a great sense of humour. He has a big heart at the end of the day."
Booing erupted after Vettel's wins in Belgium and Italy, and surprisingly at the less partisan circuit of Singapore, as Vettel moved closer to a fourth straight world title.
On Sunday night, he led from pole position to the chequered flag in an astounding, if not terribly viewer-friendly, demonstration of uncatchable front-running.
But there is also residual anger after Vettel controversially ignored team orders and passed team-mate Mark Webber to win the Malaysian Grand Prix in March.
While Vettel apologised to Webber at the time, he later struck a defiant tone and insisted he would do the same again. Webber has announced his departure from the team at the end of the season.
You’ve hit 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
Access to Exclusive Premium Stories Online
Over 30 behind the paywall stories daily, handpicked by our editors for subscribers


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