Yes, Lord Krishna is omnipresent, which means He is present everywhere.
“The Supreme person is greater than all, and although He is present on His supreme abode, He is also present everywhere, and He is attainable by unalloyed devotion.” (Lord Krishna, Bhagavad-Gita 8.22)
The sun is situated in one place but the sunshine is everywhere in the universe. In a similar way, Lord Krishna is always situated in one place on His abode, but He is also present everywhere within this universe and in the millions of other universes. If the material sun, which is a creation of God, is all pervading, meaning the sun is present everywhere, then why can’t the person who has created the sun also be all pervading?
“I am the super soul, situated within the heart of all living beings. I am the origin, the middle, and the end of all living beings.” (Lord Krishna, Bhagavad-Gita 10.20)
Those who are against deity worship limit the greatness of God. As they cannot understand that God is all pervading. This means God must be present everywhere, including within the deities.
Lord Krishna is present in the heart of all living beings as the super soul. He is present in every atom, and He is also present on His own planet called “Goloka Vrindavan”. We can only say that God is present everywhere, if He is also present in the atom, otherwise we cannot say that God is present everywhere.
“I exist within everything, and I am therefore the essence of the atomic constituents of material elements. (Lord Krishna, Srimad-Bhagavatam 11.15.12)
A person who is present everywhere must be greater than a person who is not present everywhere. Thus, God must be present everywhere because He is great. God is great means God has to be smaller than the smallest and bigger than the biggest. Lord Krishna is the smallest as He is present within the smallest particle, atom. Lord Krishna is also the largest. In His form as Maha-Vishnu, He is so big that millions of universes are coming out of the pores on His body with every exhalation, and with every inhalation, the universes go back into His body. Can you imagine how big, how small, and how great Lord Krishna (God) is?