The News Agency of Nigeria (NAN) reports that both sides’ draw is one of the toughest of the eight groups in the club football flagship competition.
Also, Bayern Munich, Guardiola’s immediate-past club, were given a quick chance to avenge last season’s semi-final defeat by Atletico Madrid after they were drawn together.
On their part, English Premier League winners Leicester City will face Porto, Club Bruges and Copenhagen on their debut.
Elsewhere, holders and 11-times champions Real Madrid renew their recent rivalry with Borussia Dortmund.
Barca and City were drawn in Group C alongside Borussia Moenchengladbach and former European champions Celtic, with recent history clearly favouring the Catalans.
Spanish coach Guardiola, who won the Champions League twice with Barca, suffered a 5-3 aggregate defeat when he faced his old team with Bayern in the semi-finals two seasons ago.
City, who visit the Nou Camp on Oct. 19, met Barca in the round of 16 in 2013-14 and 2014-15 and lost both legs on each occasion.
Bayern, now under triple Champions League winner Carlo Ancelotti, and Atletico are clear favourites to progress from Group D.
The group also features PSV Eindhoven and Russian league runners-up Rostov who are also group-stage debutantes.
Ancelotti was cautious while reacting, however, pointing out that Atletico needed a penalty kicks shootout to beat PSV last season and that Rostov eliminated Ajax Amsterdam in the playoffs this week.
“It’s a difficult draw and we have to be careful,’’ he said.
Real Madrid and Dortmund should go through from Group F at the expense of Sporting and Legia Warsaw, who are back in the group stage after a 20-year absence.
Dortmund knocked out Real in the semi-finals in 2013 but the Spanish giants came out on top the following season in the last eight.
“It’s difficult but attractive. Matches against Real are becoming classics for Dortmund. We are looking forward to meeting the holders,’’ said Dortmund coach Thomas Tuchel.
Apart from the odd heavyweight clash, many of the groups look predictable, a criticism that has increasingly been levelled at the competition in recent years.
Leicester, the other newcomers among the 32 teams, and Porto will start as favourites in Group G even though the English side are taking part for the first time.
Porto are in the group stage for the 21st time, a record they share with Real and Barca.
But the double champions from Portugal have won only three of their last 16 ties against English teams in the competition.
Paris St Germain and Arsenal, who are attempting to reach the round of 16 for the 17th time in a row, are the favourites in Group A.
They are up against Basel and rank Bulgarian outsiders Ludogorets, although the Swiss have caused upsets in the past.
Juventus, Serie A winners for the last five seasons, face Sevilla, Olympique Lyonnais and Dinamo Zagreb in Group H, with the first three likely to battle for the top two places.
For the third season running Serie A has only two teams in the group stage, and the other side, Napoli, will meet Benfica, Besiktas and Dynamo Kiev in Group B.
Group E is arguably the most evenly-balanced with CSKA Moscow, Bayer Leverkusen, Tottenham Hotspur and Monaco.
Meanwhile, the competition’s organisers, UEFA, are now under pressure from the big clubs to reform the competition.
It is likely they will change the format from 2018/2019 to allow four guaranteed places for England, Spain, Italy and Germany.
UEFA, which have faced talks of a breakaway Super League, have said only that they were studying possible changes for the 2018-21 cycle.
Full group stage draw
Group A: Paris St-Germain (France), Arsenal (England), Basel (Switzerland), Ludogorets (Bulgaria).
Group B: Benfica (Portugal), Napoli (Italy), Dynamo Kiev (Ukraine), Besiktas (Turkey).
Group C: Barcelona (Spain), Manchester City (England), Borussia Monchengladbach (Germany), Celtic (Scotland).
Group D: Bayern Munich (Germany), Atletico Madrid (Spain), PSV Eindhoven (Netherlands), Rostov (Russia).
Group E: CSKA Moscow (Russia), Bayer Leverkusen (Germany), Tottenham (England), Monaco (France).
Group F: Real Madrid (Spain), Borussia Dortmund (Germany), Sporting Lisbon (Portugal), Legia Warsaw (Poland).
Group G: Leicester City (England), Porto (Portugal), Club Brugge (Belgium), FC Copenhagen (Denmark).
Group H: Juventus (Italy), Sevilla (Spain), Lyon (France), Dinamo Zagreb (Croatia).
• Sept. 13 and Sept. 14 – First round of group matches
• Dec. 6 and Dec. 7 – Final round of group matches
• Feb. 14 and 15/Feb. 21 and 22 – Round of 16, first leg
• March 7 and 8/March 14 and 15 – Round of 16, second leg
• April 11 and April 12 – Quarter-finals, first leg
• April 18 and April 19 – Quarter-finals, second leg
• May 2 and May 3 – Semi-finals, first leg
• May 9 and May 10 – Semi-finals, second leg
• June 3 – Final (Cardiff)