A statement from the presidency confirmed that the bill, which it said "consolidates various laws relating to marriage", had been signed into law.
The bill, which amended existing legislation, was passed by parliament last month to formalise traditional practice regarding marrying more than one person.
"Marriage is the voluntary union of a man and a woman, whether in a monogamous or polygamous union," the presidential statement added.
The initial bill had given a wife the right to veto the husband's choice, but male members of parliament overcame party divisions to push through a text that dropped this clause.
The National Council of Churches in Kenya (NCCK), which groups more than 40 churches and Christian organisations from across the east African nation, has also spoken out against the bill.
The national Federation of Women Lawyers (FIDA Kenya) has also said it would mount a legal challenge against the law.
"We know that men are afraid of women's tongues more than anything else," female legislator Soipan Tuya told fellow MPs when the bill was passed.
"But at the end of the day, if you are the man of the house, and you choose to bring on another party -- and they may be two or three -- I think it behoves you to be man enough to agree that your wife and family should know," she added.
Many have said the legislation merely acknowledges something that is already widespread.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
