Thomas Brady Cullinan (15 May 1906 - 11 April 1940), known professionally as Tommy Cullinan, was an Irish jockey who, in 1930, became the first to secure the unofficial Triple Crown of National Hunt racing in a single season, riding the winning horse in the Grand National, the Cheltenham Gold Cup and the Champion Hurdle.

[3] Cullinan began riding as an amateur jockey in the 1923 Irish National Hunt racing season aged 16.

[6] In the Tower Handicap Steeplechase Cullinan's new career got off to an auspicious start, riding Tiranogue to victory by half a length.

Cullinan remounted Billy Barton and was the only other Jockey to complete the course; the fewest recorded finishers in Grand National history.

[11] In October of that year Cullinan was appointed first jockey to American owner, John Hay Whitney, whose horses - including Easter Hero - were trained under Jack Anthony at Wantage.

[12] As a result, Cullinan was partnered with Easter Hero for both the Cheltenham Gold Cup and Grand National the following Spring.

At the 1930 Cheltenham Festival Cullinan was first partnered with Brown Tony - another product of Anthony's stable - for the fourth annual running of the Champion Hurdle.

Brown Tony took the win ahead of favourite Cleer Cash and Peertoi, though the three horses crossing the judge's line of vision almost together.

But when Gib fell at the penultimate fence, Easter Hero was clear to take a twenty length victory, becoming the first horse to win back-to-back Gold Cups.

"[15] However, in claiming Gold Cup victory, Easter Hero sustained a tendon injury and had to be withdrawn from the 1930 Grand National at Aintree three days before the off.

It meant that Cullinan would be unable to partner his intended mount, a race for which the duo had been the ante-post favourite after their success at Cheltenham.

[16] Cullinan was instead belatedly partnered for the 1930 Grand National with Shaun Goilin, trained by Irish trainer Frank Hartigan at Weyhill, Hampshire for owner Walter H. Midwood.

Despite good going only five of the 41 starters of the 1930 Grand National would stay the course and the result remains among the closest finishes on record.

The field gradually thinned down, but no matter what came along to join us in the front rank, I felt my horse going strongly, and I had no fear.

[22] Cullinan followed up the last of these wins by completing an Aintree double, riding Kakushin to victory in the Champion Steeplechase on the same afternoon.