(credit: www.VisitKorea.or.kr)
Singapore Airlines
Singapore to Seoul
From $716
Outbound Travel: 5 Oct 2015 to 23 Mar 2016
Min passenger: 1
Min / Max duration: 2 days / 1 month
Ticket sales period: 8 Apr to 5 May 2015 (promotion ended)
http://www.singaporeair.com/booking-flow.form?execution=e2s1
Singapore to Seoul
From $668
Outbound Travel: 25 Aug 2015 to 11 Feb 2016
Min passenger: 1
Min / Max duration: 2 days / 1 month
Ticket sales period: 8 Jan to 31 Mar 2015 (promotion ended)
http://www.singaporeair.com/booking-flow.form?execution=e1s1
Singapore to Seoul
From $688
Outbound Travel: 7 Jul to 29 Nov 2015
Min passenger: 1
Min / Max duration: 3 / 14 days
Ticket sales period: 8 Jan to 31 Mar 2015 (please see revised promo above)
URL: http://www.singaporeair.com/booking-flow.form?execution=e1s1
Asiana Airlines
Singapore to Seoul
From $748
Outbound Travel: 1 Aug to 19 Nov 2015
Min passenger: 1
Min / Max duration: 2 days / 1 month
Ticket sales period: 1 to 30 Jun 2015 (promotion ended)
http://ea.flyasiana.com/C/en/main.do
Singapore to Seoul
From $755
Outbound Travel: 21 Jun to 2 Sep 2015
Min passenger: 1
Min / Max duration: 2 days / 1 month
Ticket sales period: 1 to 30 Apr 2015 (promotion ended)
URL: http://ea.flyasiana.com/C/en//boardContents.do?menuId=004002001000000&menuType=BOARD&boardCode=BOARD_EVENT&eventCateCode&eventSeq=3324&boardCmd=VIEW
Cathay Pacific
Singapore to Seoul (For HSBC Credit Card Holders)
From $608
Outbound Travel: 17 Jun to 17 Dec 2015
Min passenger: 1
Min / Max duration: up to 1 month
Ticket sales period: 17 Jun to 14 Jul 2015
http://www.cathaypacific.com/cx/en_SG/flightoffer.hsbc-special-fares.special-fares-hsbc.html?cm_mmc=CXpecials-SG-_-HSBCJP-SINMULTI-10JUL15-_-HS-_-10JUL2015&cm_lm=GS-677D981751FC75E00A4DD010C4510C60
Singapore to Seoul (For UOB Credit Card Holders)
From $708
Outbound Travel: 1 Aug to 18 Dec 2015
Min passenger: 2
Min / Max duration: up to 1 month
Ticket sales period: not stated (promotion has ended)
http://www.cathaypacific.com/cx/en_SG/flightoffer.early_grab_sales_uobcards.html
For Winter 2015 promotions, please click on this link.