The former amateur rider and eventer will be represented by Lady Hollywood in the Grade 1 Breeders' Cup Juvenile Turf Sprint at Keeneland on November 4.
Haynes said: "This is my first proper season training and to be having a runner at the Breeders' Cup is unbelievable. It's all very exciting. We hope for a good draw and that the rain stays away.
"Lady Hollywood is in good form and has had a nice break since her win in France. She's now 12kg over her last run, but she has actually filled out and got a lot stronger. She'll go to Chelmsford next week for a gallop and then she flies out next Saturday."
When she goes to post in Kentucky, the Amo Racing/Omnihorse Racing-owned filly will have had a two-month break.
The daughter of Havana Grey provided Haynes's Cadland Cottage stable with its first black-type win at Naas in July, but topped that when landing the Group 3 Prix d'Arenberg at Longchamp at the beginning of September.
Winner of four of her seven starts, Lady Hollywood will be ridden in the five-and-a-half-furlong sprint, which has a purse of $1 million, by US-based Umberto Rispoli.
Mickael Barzalona rode Lady Hollywood in France and Haynes said: "We've booked Umberto Rispoli to ride her and he's quite a big deal over there and knows the track well. The owners wanted an American jockey."
Lady Hollywood is a 20-1 chance and Haynes added: "It will be a different level of competition over there and she'll be taking on the boys again, as she did in France, but she'll be getting the weight allowance, which is helpful.
"We haven't gone to the well too often, so hopefully she's fresher than most, and she could run a big one with a low draw as she shows good gate speed and likes to sit handy."