Green’s Dictionary of Slang

tiny, small, insignificant; often preceded by ‘little’.

1905		J.W. Carr ‘Words from Northwest Arkansas’ in DN III:i 87: little bitty, little bitsy, adj. Little, tiny. ‘They were little-bitty/bitsy fellers.’.
1913		H. Kephart Our Southern Highlanders (1922) 94: You know a feist is one o’ them little bitty dogs that ginerally runs on three legs and pretends a whole lot.
1923		R. McAlmon Companion Volume 199: Do have a drink with me dear, just one wee little bitty drink.
1940		(con. 1820s) W.E. Wilson Wabash 203: ’Tain’t nothin’ but a little-bitty hand-horse mill.
1941		A. Lomax Mister Jelly Roll (1952) 19: They’d press a button in their pocket and light up the little bitty bulb.
1952		J. Jones From Here to Eternity (1998) 225: There was a little bitty Jewboy standin lookin at it.
1961		G.L. Coon Meanwhile, Back at the Front (1962) 108: He was just a little bitty guy.
1969		B. Jackson Thief’s Primer 130: If I’m going to trial [...] I like to have me a little bitty young lawyer, a fire burner.
1977		Sun. Mirror 21 Aug. 9: He chomped down on these little bitty things.
1980		E. Folb Runnin’ Down Some Lines 30: Use a get to me when I’z little bitty dude.
1986		L. Heinemann Paco’s Story (1987) 129: We’d prowl up and down the streets and little-bitty side alleys.
1999		Observer Mag. 22 Aug. 12: The ones they use today are little bitty pops, like caps.
2006		C. Carr Our Town 272: ‘A little bitty group like ours,’ Thompson said.
2012		D. Whish-Wilson ‘In Savage Freedom’ in Crime Factory: Hard Labour [ebook] Ogilvie, hoping to turn me, loading me for bitty possession.