Lindsley Williams, a 39-year-old zoning activist from the Woodley Park section of Northwest who holds a master's degree in urban and regional planning, has been nominated to a four-year term on the D.C. Zoning Commission by Mayor Marion Barry. The appointment is subject to confirmation by the City Council, which usually holds hearings on such nominations. A hearing on Williams' nomination has been scheduled for March 19.

Williams, a senior policy official of the National Institute of Mental Health in Rockville, has helped fight neighborhood zoning and planning battles for the past 10 years.

As president of the Woodley Park Community Association from 1973-76, he participated in negotiations with Metro that led to the relocation of a proposed air conditioning facility for the Woodley Park-Zoo stop on the Red Line. As chairman of the Planning and Zoning Committee of Advisory Neighborhood Commission 3C -- covering Woodley Park, Cleveland Park, McLean Gardens and Massachusetts Heights -- Williams helped lead a still-unresolved neighborhood struggle to persuade the Sheraton Park Hotel (now the Sheraton Washington Hotel) at Woodley Road and Connecticut Avenue NW to increase the number of parking spaces in its expanded facility.

He also has been active in the Wisconsin Avenue Corridor Committee, a group of Northwest residents concerned with land-use issues. As chairman of the Transportation Committee, he helped gather proposals from community groups regarding zone recommendations for Ward 3.

He also is a member of the board of directors of the D.C. Citizens Planning Coalition and testified on behalf of the group in recent zoning commission cases concerning hotels and planned unit developments. The coalition has discouraged hotel construction in residential areas and is against reducing the minimum lot size for planned unit developments. It was the coalition that asked the mayor to consider Williams, along with several other candidates, for the zoning commission vacancy.

The five-member zoning commission makes the rules about where and what kind of development may take place in the city. In a telephone interview, Williams said he would resign his civic association offices to take the commission position. He said he would decide on a case-by-case basis and with the advice of the corporation counsel whether to participate in future zoning cases concerning matters in which he previously has been active.

Zoning commissioners usually are paid $100 a day for each day that the commission meets. But since Williams is a federal employe, he would have to take a leave of absence without pay to be compensated for meetings. Instead, Williams said he would serve on the commission without pay.

If confirmed, Williams will replace Theodore F. Mariani, an architect and engineer whose four-year term will expire when his replacement has been confirmed. Citizens groups often have criticized Mariani as too favorable to development interests.

Helen Wood, a charter member of the Citizens Planning Coalition and past president of the Wisconsin Avenue Corridor Committee, says, "Mariani has tended to favor maximum development regardless of citizen concerns for neighborhood protection and historic preservation. I think Williams will take a more balanced view."

Two zoning commission members -- George White, architect of the Capitol, and John Parsons, who represents the director of the National Park Service -- automatically serve because of their offices. The mayor appoints the other three members. Currently serving are Ruby B. McZier, an attorney, whose term expires in 1982 and Walter B. Lewis, professor in the School of Architecture and Planning at Howard University, whose term expires in 1983.