Elections to the Bombay Legislative Assembly were held on February 25, 1957. 1146 candidates contested for the 339 constituencies in the Assembly. There were 57 two-member constituencies and 282 single-member constituencies.
Bombay Legislative Assembly election, 1957 Wikipedia
On 1 November 1956, under States Reorganisation Act, 1956, Bombay state was enlarged by the addition of Saurashtra state and Kutch state, the Marathi-speaking districts of Nagpur Division of Madhya Pradesh, and the Marathi speaking Marathwada region of Hyderabad. The state's southernmost Kannada-speaking districts of Dharwar, Bijapur, North Kanara and Belgaum (excluding the Chandgad taluk) were transferred to Mysore state, while Abu Road taluk of the Banaskantha district was transferred to Rajasthan. Hence the constituencies increased from 315 to 396 in 1957 elections.