Racing for the first time in 10 months, Commonwealth champion Olli Hoare has led a host of big names into the 1500m finals at the Australian track and field championships in Adelaide.

Fully recovered from hernia and pelvis injuries that ruled him out of last year's world titles in Budapest, the 27-year-old Hoare clocked the fastest men's heat time of three minutes 38.80 seconds on Thursday.

It was a commanding return for a man whose previous competitive run was at the Oslo Diamond League meet in June last year, when he broke the Australian 1500m record.

The final on Saturday will be a heavyweight showdown, with Tokyo Olympics finalist Stewart McSweyn (3:39.67) and teen sensation Cameron Myers (3:41.54) looking every bit as impressive as Hoare in winning the other two heats on Thursday.

Joining them in the title race will be defending national champ Callum Davies and much-improved duo Jesse Hunt and Adam Spencer.

The winner of Saturday's final - and perhaps also the runner-up - will likely be guaranteed a spot in the Paris Olympics team at the conclusion of the national titles on Sunday.

It was a similar scenario in the opening round of the women's 1500m, with Tokyo Olympics finalists Jessica Hull (4:14.08) and Linden Hall (4:15.23) the standout performers along with the consistent Georgia Griffith.

Australia currently enjoys unprecedented strength in depth in the middle-distance events.

If anything, the field is even deeper in the women's 800m where national record holder Catriona Bisset, teen sensation Claudia Hollingsworth, Bendere Oboya and Abbey Caldwell will square off in the opening round on Friday.

All four have already bettered the tough Olympic qualifying mark of 1:59.30.

All five of Australia's in-stadium medallists at last year's world championships - pole vaulters Nina Kennedy and Kurtis Marschall, high jumpers Eleanor Patterson and Nicola Olyslagers, and javelin thrower Mackenzie Little - will also be in action over the weekend in Adelaide.

The Australian track and field team for the Paris Olympics is expected to number roughly 70 athletes if both 4x100m relay teams qualify.