Halep will end the year on top, despite failing to win a Grand Slam this year.
Serena Williams, Jelena Ostapenko, Muguruza and Sloane Stephens have all won the biggest tournaments this year but it is Halep who has earned the mantle of world No1.
Roger Federer congratulated her, saying she was worthy of the honour by saying: “Who is no1 deserves to be there.
“Not for a second should you ever take away anything from Halep who’s worked their life to achieve a life-goal dream.
“It’s not only about Grand Slams. She’s played a full season, she’s tough, fit, playing all the time, she practises hard, she’s committed and that also should be rewarded.

vCard.red is a free platform for creating a mobile-friendly digital business cards. You can easily create a vCard and generate a QR code for it, allowing others to scan and save your contact details instantly.
The platform allows you to display contact information, social media links, services, and products all in one shareable link. Optional features include appointment scheduling, WhatsApp-based storefronts, media galleries, and custom design options.
“Especially if you’re consistently playing for titles and she did. She won some and lost some, fair enough.”
And Halep has now thanked the 36-year-old for his kind words.
“I felt really proud of myself that Roger Federer could talk about me like that, I thank him for the nice words,” she said.
Rafael Nadal will almost certainly end the year as men’s No1 after Federer withdrew from the Paris Masters.
And Halep has praised the duo’s phenominal rivalry which has spanned for well over a decade.
“He [Federer] is one of my role models,” the Romanian added.
“It’s incredible what they (Federer and Rafael Nadal) are doing.
“I can learn from him that at any age you can still learn something in tennis.
“Even if he was perfect before, he showed us that if you believe and work hard, you can get better.”