"1st Wife: Greta Kukkonen (m. 1942, div. 1955, three sons)
Son: Jonathan (b. 1944, d. 1975 suicide gunshot)
Son: Stephen (b. 1945, served in Vietnam)
Son: Carey (b. 1949)
2nd Wife: Veronique Passani (m. 31-Dec-1955, until his death, one son, one daughter)
Son: Tony Peck (b. 1956)
Daughter: Cecilia Peck (b. 1958)"
another good source:
"In October 1942, Peck married Finnish-born Greta Kukkonen with whom he had three sons. Greta was awarded the Rose of Finland, equivalent to a Medal of Freedom. They were divorced on December 30, 1955, but maintained a very good relationship as parents to their sons, Jonathan, Stephen and Carey Peck. Jonathan Peck, a television news reporter, committed suicide in 1975. Stephen Peck is active in support of American veterans from the Vietnam war. His first wife is screenwriter Kimi Peck who co-wrote Little Darlings with Dalene Young. Carey Peck had political ambitions and ran for United States Representative in California, with the support of his father and family. He narrowly lost to conservative Republican Bob Dornan.
On December 31, 1955, the day after his divorce was finalized, Gregory Peck married Veronique Passani, a Paris news reporter who had interviewed him in 1953 before he went to Italy to film Roman Holiday. He asked her to lunch six months later and they became inseparable. They had a son Anthony Peck, and a daughter Cecilia Peck. They remained happily married until Gregory Peck's death.
Peck had grandchildren from both marriages. Stephen has a daughter named Marisa, and a younger son named Ethan. Carey has four children, three daughters Marisa, Isabelle, and Jasmine, and a son Christopher. Anthony has a son, Zack, with model Cheryl Tiegs. Cecilia has two children with writer Daniel Voll, son Harper and daughter Ondine."