Dec. 23, 2013 3:42 p.m. ET
Twitter Inc. co-founder Jack Dorsey is joining Walt Disney Co.'s board of directors, the second Silicon Valley executive to do so.
Mr. Dorsey is taking a spot that will soon be vacated by former Cisco Systems Inc. executive Judith Estrin, who has been on Disney's board since 1998 and is stepping down per a company policy that limits tenure to 15 years.
He joins Facebook Inc. chief operating officer Sheryl Sandberg on Disney's...