No female horse has won the annual honor since Lady's Secret in 1986.
Thoroughbred racing hands out its 2002 awards in a black-tie affair.
Azeri won eight times in nine starts last year, including an overpowering victory in the Breeders' Cup Distaff. She already is assured of winning the Eclipse Award as champion older filly or mare since she is the only finalist.
Some voters could stay away from Azeri since she ran in races restricted to fillies and mares.
War Emblem, the winner of the Kentucky Derby and Preakness, figures to be the most prominent challenger for Horse of the Year, but War Emblem came up short in the Belmont Stakes and the Breeders' Cup Classic, possibly hurting his chances.
Other Horse of the Year finalists are Rock of Gibraltar, an Irish horse trained by Aidan O'Brien, and Left Bank.
War Emblem also is a finalist for top three-year-old colt, along with Medaglia d'Oro, the winner of the Travers Stakes, and Came Home, who won the Santa Anita Derby and beat some older horses in the Pacific Classic.
Rock of Gibraltar raced just once in the United States, losing in the Breeders' Cup Mile. Left Bank, who died last fall from complications from colic, posted his biggest wins in the seven-furlong Tom Fool Handicap and the Whitney Handicap.
Left Bank also is a finalist for both champion older male and champion sprinter. The other finalists for champion older male are Street Cry, who was second in the Whitney and won the Dubai World Cup, and Stephen Foster Handicap, and Volponi, the stunning winner of the Breeders' Cup Classic.
Orientate, the Breeders' Cup Sprint winner, is the favorite in the sprinter category. The other finalist is Xtra Heat, who won seven of 11 starts last year.
A horse without a win in the United States has yet to win an Eclipse Award, but Rock of Gibraltar could break through as a finalist for the top male turf horse. The other finalists in that category are High Chaparral, who won the Breeders' Cup Turf, and With Anticipation, who three Grade I races.
Bobby Frankel won 14 Grade I races and is a finalist for top trainer, an award he has won three times previously. The other finalists are Steve Asmussen, who led the nation with 407 winners, and Laura de Seroux, the trainer for Azeri.
Surprisingly absent from the list of finalists is Bob Baffert, who trained War Emblem and Vindication.
The overwhelming favorite for champion two-year-old filly is Storm Flag Flying, the unbeaten winner of the Breeders' Cup Juvenille Fillies.
Vindication, an early favorite for this year's Kentucky Derby and won the Breeders' Cup Juvenile, is favored to be named champion two-year-old male.
The finalists for top three-year-old filly include Farda Amiga, who won the Kentucky Oaks and Alabama Stakes.
There are 228 voters for the awards this year, which are chosen from the National Thoroughbred Racing Association, the Daily Racing Form, Equibase, and the National Turf Writers Association.