Abraham, 24, was last included in England squad in November 2020. Southgate's initial 23-man squad was announced on Thursday.
The 24-year-old has been in great form since joining Roma from Chelsea in a £34million deal in August, scoring four goals in 10 appearances in all competitions for the Serie A club.
Chilwell, meanwhile, has also been selected for the upcoming qualifiers during the two-week international break.
The Chelsea left-back scored in the Blues' 3-1 victory over Southampton on Saturday.
England play in Andorra on Saturday and then face fellow Group I rivals Hungary at Wembley on Tuesday.
England said: "Ben Chilwell and Tammy Abraham have been added to the England squad for the forthcoming FIFA World Cup qualifiers.
"All players will report to St George's Park on Tuesday apart from Reece James, who is ruled out through injury."
James was forced off during Chelsea's recent home defeat to Manchester City due to an ankle injury and missed Wednesday's Champions League defeat to Juventus in Turin and Saturday's home win against Southampton.