RINGLING BROS. AND BARNUM & BAILEYMadison Square Garden, (212) 507-8900. Season runs through April 2.

IF you can’t run away to join the circus, let the circus join you.Your latest chance arrived in full force at Madison Square Garden Thursday night, with the seasonal arrival of the Ringling Bros. and Barnum & Bailey circus.

It’s still modestly — and not all that inaccurately — billed as “The Greatest Show on Earth.”

It is surely an unequaled bang for your buck.

Started in 1871 as a one-ring circus by P.T. Barnum, it’s now a national institution spread over three centuries.

Now preserved by Kenneth Feld, the charms of its dashing glitz and trashy dazzle remain totally undimmed by virtue of the designers Eduardo Sicangco and Scott Lane.

And after seeming to play tentative footsie with the arty trend of boutique circuses such as Le Cirque de Soleil, the old three-ringer of Ringling Bros. and Barnum & Bailey has happily reverted to type.

The tumpty-tumpty, red-nosed raucousness is back, and so are old-time circus traditions, such as horses, elephants, big cats, floppy clowns and acrobats.

But there are also dozens of pretty dancing girls and a young ringmaster — the 33rd in 130 years — the very personable Michael James McGowan, who can really sing.

The marquee/poster act this year is “Sara and the Tigers.”

Sara is a 22-year-old, British-born, European-schooled, blonde who is as beautiful as the Bengal tigers she plays with.

She may not be the most sensational animal trainer we’ve ever had, but unquestionably she’s the best looking, and her tiger-manner is unquestionably in keeping with our times.

All the animals look good, happy and beautifully cared for — but the humans are even brighter.

The trapeze and trampoline maestros, the Argentine aerialists, a gung-ho troupe of 18 female bicycle gymnasts from China and five Russian clown gymnasts offer plenty to watch.

My personal favorites were Anton Beliakov — originally from the Moscow State Circus — who has an act of extraordinary grace, flying on straps high above the arena, and the Quiros, a high-wire act from Madrid who do 21 impossible feats with no safety net.

Finally, there is a strange double act of Michu (claimed to be, at 33 inches tall, “the smallest man on earth”) and a remarkably versatile, chainsaw-wielding clown, Jon Weiss.

So the good old circus is back in town.

If you get there early, you can take part in what they’re calling the “Three-Ring Adventure,” where you can mingle with the performers and animals and get autographs (don’t try the tigers).

On display are the rhinestone necklace, bracelets and earrings worn in March 1955 by Marilyn Monroe, when she triumphantly rode a pink elephant at a fund-raising gala.

Although my pink elephant days are long past, that is one I wouldn’t have minded seeing.