The Italian, who managed Leicester between 2015 and 2017, arrived at the ground to lay a wreath in memory of his former boss, whose image stands at the front of the tributes.
Leicester supporters continue to arrive in their droves to pay their respects to the 61-year-old, who in his eight years as owner saw the club earn promotion to the top flight and produce the unthinkable.
A sea of flags, shirts, scarves and flowers have been left outside of the stadium since the tragedy.
Ranieri was joined by his wife, Rosanna, Vichai's son, Aiyawatt, and wife, Aimon, as he laid the wreath before pausing for a few moments and saying a prayer in memory of him.
Ranieri, who watched another former club Chelsea play Derby in the Carabao Cup on Wednesday night, spoke emotionally about Srivaddhanaprabha earlier this week.
He told Sky Italia: "I was terribly shaken by the news.
"He was a good man and always had a positive word for everyone. His positivity and ability to make everybody love him was clear for all to see.
Leicester fans sing heartfelt song about late owner Vichai Srivaddhanaprabha during late night vigil
"He came into the dressing room only to dispense kind words, never to reproach you.
"He was an illuminated man and everything he touched became better.
"Now it's up to his son (Aiyawatt), who has always been in love with football, to carry on in his father's footsteps."
The funeral of Srivaddhanaprabha will begin in Thailand on Saturday, with a series of recitation ceremonies continuing over a period of seven days.
In recognition of Vichai's standing in the country, the funeral has been granted "Royal sponsorship".
Jamie and Rebekah Vardy lay wreath to Leicester owner Vichai Srivaddhanaprabha who died in helicopter crash