Conor McGregor Flossin' w/ Versace, Rita Ora & Lewis Hamilton at Fashion Awards

Here's Conor McGregor and Lewis Hamilton proving you don't have to be in the NBA to be sports fashionistas ... stuntin' like bosses at the annual Fashion Awards show in London.

The UFC and F1 mega-stars pulled up to the red carpet at Royal Albert Hall on Monday night and posed for some pics with fashion icon Donatella Versace -- who was honored at the ceremony.

Conor was no doubt rockin' one of his custom David August suits ... but Lewis might've outdone the champ with his bright-red plaid joint.

McGregor and Hamilton kept the party going inside the venue -- rubbing elbows with Rita Ora and supermodels Irina Shayk and Jourdan Dunn.