Are there luggage lockers or storage options at BKK Airport?

Yeah don't the bottom

Not cheap, and closes at night.

Suwarnabumi airport, BKK, 2nd floor, near gate 8. See pic.

Suvarnabhumi Airport Bangkok-Suvarnabhumi Airport

You can also leave your bags at Suvarnabhumi Airport, on Level 4 in the Baggage Claim in the Departure area. Behind counter Q you can leave your bags for 100 baht per day per bag. There are also other baggage storage and delivery options:

AIRPORTELs

one of the most popular baggage agencies at BKK airport, charges fees for baggage storage that depend on the size of the baggage: storing normal baggage (25 kg or less) costs 100 THB per unit per day, storing special baggage (non-baggage items) costs 200 THB per day. Longer storage is charged at a reduced rate: storage for 5-7 days costs 500 THB, storage for 30 days - 2000 THB.

LuggAgent

also offers luggage storage services at Suvarnabhumi Airport. The luggage stored here can be a suitcase, box, backpack or bag (briefcase), but each piece of luggage must not be larger than 32 inches (length and width total 180 cm) and weigh no more than 32 kg. Luggage storage offered by LuggAgent usually costs 93 THB per piece of luggage for a day. If you book luggage storage online, you can get a discounted rate (81 THB per day).

Bellugg Left Luggage Office

for luggage storage fees depending on the size of the luggage. S size luggage (less than 22 inches) can be stored here for 90 THB per day, M size luggage (22 to 26 inches) - 120 THB per day, oversized luggage - 150 THB per day. The rate is calculated for each piece of luggage per 24-hour period.

No lockers but a storage facility.

Yes

@Jack ***************

Yes there is a luggage storage room there.

Why you didn't try to search in Google?

At the bottom floor, luggage keeping counters