Zed

Zed is one of the worst counters for veigar. He can leap through your E, the only source of CC, and give extreme damage.

LeBlanc

Another bad counter for Veigar. It can be very hard to keep LeBlanc in control and give some damage to her + due to your squishiness, she can easy get you low if she lands a good combo.

Katarina

Basically the same as LeBlanc.

Vladimir

A very hard counter for veigar too. He can gain HP fast, so it's impossible to do enough damage. He can also go through your E, which can be hard to live without. Just remember his CD.

Karthus

His poke and damage can outplay you instantly.

Fizz

He can jump through your E and give some damage. Just focus on his CD, and you'll be fine.

Ekko

Can be hard to counter especially when he has ult available. When you send your R to him, he can easily defend it by ult. He can also land some damage on you, focus to dodge.

Yasuo

He can be annoying to deal with, just focus to autoattack him once, when he has his sheald. Then poke him and it'll be all good. If he windshields, go besides it, combo, and you'll be good.

Xerath

He has very long range, and can give much damage to you.

Ahri

Lux

Talon

Aurelion Sol

Brand

Galio

Diana

Kassadin