Carlo Ancelotti's side will parade the league trophy on Sunday in the Spanish capital and a side filled with reserves made light work of the downtrodden Andalucians.
Brahim Diaz struck twice with Fran Garcia and Arda Guler also on target for Madrid, who defeated Bayern Munich in midweek to reach the Champions League final.
Los Blancos secured their 36th Spanish title last weekend with four games to spare, but chose not to celebrate to focus on the Bayern clash.
A late Joselu brace settled that match in dramatic fashion and the Spaniard started up front against Granada, with only Antonio Rudiger starting the match from the side that beat the German giants.
Granada, 19th, were relegated before kick-off after Mallorca beat Las Palmas to ensure the Andalucians could not escape the drop zone.
Their players gave Real Madrid a guard of honour and Los Blancos went on to demonstrate the focus that drove them on to the title, even with nothing on the line now. Victory sent them 15 points clear of second-placed Girona.
Madrid took the lead after 38 minutes when Diaz cut the ball across the six-yard box and Garcia arrived to stroke home.
The left-back turned creator for Madrid's second goal in stoppage time before the break, feeding Turkish teenager Guler, who took a touch to control and a second to fire into the bottom corner.
Madrid maintained their dominance in the second half and extended their lead after 49 minutes.
Tricky playmaker Diaz received the ball on the halfway line and drove forward deep into Granada territory. With the defence standing off he worked his way into the area and fired home.
The Morocco international added the fourth after a neat team move, finishing comfortably after veteran midfielder Luka Modric teed him up.
The likes of Jude Bellingham, Vinicius Junior and Fede Valverde stayed on the bench for Madrid, while goalkeeper Thibaut Courtois completed his second game back after nine months out injured.
The three remaining league fixtures will allow Ancelotti to rest and rotate to get his first choice side in optimal condition to face Borussia Dortmund at Wembley on June 1 in the Champions League final.
They may also provide fans a last chance to see Modric in action, with the 38-year-old Croatian's contract expiring in the summer.
When Modric made way for Toni Kroos in the second half many fans at the Nuevo Los Carmenes stadium applauded him off.
